Marie, you're about to embark upon a very messy but satisfying adventure! ;) At least, that's how I view painting.

If your paint is still in good shape, you shouldn't need to prime (unless you're going from white to a very deep color, in which case you may end up using a tinted primer so it takes fewer top coats of paint to reach the true color).

While you're washing your walls, check for any places you may want to repair (dings, nail holes). You'll want to fix these with spackling & a putty knife (DAP makes a cool product that goes on pink and dries to white so you know when it's dry enough to paint over). And if you do need to fill holes, you'll need to 'spot prime' over those places, then wait about an hour for your primer to dry (read the label). Tape any areas off not to be painted (like trim or windows) and make sure you've covered floors & furniture with drop cloths, and you're ready for paint!

I work at an Ace Hardware, so this is the first place that came to mind for useful tips from start to finish (prep, picking the right sheen & tools, etc):

http://www.acehardware.com/paintingtips/index.jsp

And I found these fun tips in my bookmarks file:

http://asoftplace.net/2010/04/painting-tips-and-tricks/

I'm at an ACE too...waaaaayyy up in FRIGID (-20 expected tonite!) Fargo, ND!
(Been a member here on GW since Aug. 2006)

Yep...prep is the key!
I recommend POWDERED Dirtex to our customers. Don't have to rinse this. TSP has to be rinsed a couple times. DON'T use liquid cleaners.

When your walls are dry, follow Jessicaml's repair advice.

Because your walls are 99% likely to be a cheap "Builder's Flat", I'd prime everything. These cheap flats are pretty porous, and should be sealed-off.
This way, the 2 new topcoats you apply will show their absolute best.

>>> Use good tools, techniques, and paint. It'll make a difference in your final look.
>>> Choose appropriate sheens for the rooms' end-use.

Faron

Actually, Faron, I found GW in part because of your posts regarding Ace Cabinet & Trim paint. :) I'm not our resident "paint-expert", but I love it so I'm learning all I can...always enjoy reading your posts & learning from your experience!

That's cool Jessica!
...and Thank You!
(Faron ***blushing*** slightly here....)

Painting is one of those endeavors that is, at the same time, both easy AND tricky.
Some in-depth paint knowledge will always serve you well...as well as your customers.

Faron

There is really no need to spot prime patches anymore (at least with the paints I use). In fact, spot priming patches can actually be a bad thing when those spot primed areas flash through. My theory on why this happens is that the primer is a better sealer than the topcoat so since the wall is sealed better there, it flashes. If you are going to spot prime, I would use the actual paint itself instead of a seperate primer. But really spot priming is not necessary with modern day paints...two full coats of a quality washable topcoat is all you need. If you are going to prime, prime the entire wall, not just spots of the wall. Also, when buying patching, especially if you are going to Ace, do not buy/use that Red Devil vinyl spackle. It's absurdly hard to sand even though it says 'easy to sand' on the label and since homeowners generally apply too much patching to the wall, they end up sanding forever and still not getting the patch smooth because you almost need a belt sander. Can you tell I have a problem with Red Devil? I prefer lightweight joint compound...I'm not sure if Ace sells that, but Home Depot certainly does. It's very cheap, comes in gallon pails and is made by Sheetrock USG. What you want is the Plus3 which has the blue lid. You can also use the stuff that is tinted yellow which helps you to see it better when patching white walls, but I believe that stuff only comes in 5 gallon boxes. It is nice to be able to see where you patched though so that you don't accidentally paint over an unsanded patch. There is also another company called Pro Form I believe that makes lightweight compound.

Spot priming. :)

A wall that has been generously spot primed always makes me smile. In the time they farted around 'dotting here and dotting there' all in the name of spot priming, they could have properly primed the whole d@mn room.

I have a few, OK A lot of things, I'd like to mention from experience as a homeowner and the painter in the family. First is BUY GOOD PAINT, the best you can afford. If it's taken you 10 years to decide to paint, the last thing you want to do is use a cheap paint. You'll end up having to do it all over again in a couple of years. Also, as paintguy and funcolors mentioned, I recommend a primer over 10 year old builder walls, they will drink up paint like water. Zinsser 1,2,3 primer costs about $22 for a gallon where as some of the premium paints are between $40 and $60 a can.

Now, what is "good" paint? It depends on who you ask and what you have available in your area. Here's a list to use as a guide.

If money is no object:

Fine Paints of Europe or Farrow and Ball. Really good, once and you're done for 20 or more years kind of paint. Some people believe its worth it. I tend to change my decor scheme every few years. DH already feels I spend a fortune on paint, if I used FPE or FB, it would be a king's ransom. Plus, there aren't any dealers near me. This is probably a very good thing.

For the rest of us:

Benjamin Moore Aura. It can be tricky, especially if you've never painted before. However, since you've never painted before, you don't really have anything to compare it to. It dries fast, you basically roll or brush it on and keep going. It covers well and brush strokes disappear. I hear it's easy to touch up, but I've never had to in a year since I used it in my family room.
Benjamin Moore Regal. It's basic good paint, pretty thick and forgiving.
Benjamin Moore Natura. It's 0 Voc and has an almost herbal smell. This is good when you need to use the space and don't want a heavy paint smell.

Sherwin Williams Duration. I found it a bit fussy to work with, but the results are excellent. The pigments like to separate, so you have to stir it constantly and only put a small amount in the rolling tray at a time.
Sherwin Williams Super Paint. I've never used this, my uncle who is a GC swears by it. Of course, I know he also gets a ridiculously huge discount, so google or search this board for opinions.

ICI/Dulux - now called Glidden Professional Lifemaster. Funcolors recommended this as a good paint. Do not confuse this with the Glidden at Home Depot. It's the same manufacturer, but different formulas.

Muralo Ultra Ceramic. Hard to find, but I hear it's really great. As the name suggests, the paint has ceramic in the formula, so it's supposed to be hardwearing.

Graham or Miller Aqua Borne Ceramic. Same as above. Unfortunately, I don't have these near me or I'd give them a try.

C2. Anything you want to know, ask Faron. I'd kept my paint samples for a while and when I finally decided to do C2, I found out the paint store no longer carried that line.

Kwal - There's one practically in my backyard, but it's a very intimidating place that caters to pro painters. I've only bought a quart as a sample. They have a huge array of paint lines. They say it's good, but you'd probably have to ask them which line is best.

Pittsburgh Paint Manor House. Again, harder to find.

Porter Paint. PPG again, but their product is called Silken Touch. I don't know why.

Ace Royal. According to Faron, it's good paint for the money. So if you have a smaller budget, definitely consider the Ace. Most Ace stores also carry Benjamin Moore, so if you love the BM colors but not the price, they'll be able to mix it for you, probably better than most other stores since they have the actual paint formulas as opposed to scanned formulas.

Kelley-Moore Acry-Plex. Again, limited locations and one of those stores that seem to cater to Pros, but I've used the Acry-Plex in a previous house and I like it as well as BM Regal.

Pratt and Lambert. Pretty colors. I've only used Red Seal which went on well. It was an oops paint, that is a tinted paint where the customer didn't like the final result. I don't know how durable as I ended up repainting. I didn't like the color either.

Home Depot Behr Premium Plus Ultra. It's only been out a couple of years. I used it in a house we were selling, so I don't know how well it holds up for the long haul. I used leftover semi-gloss from that house on my current house in a very limited area on baseboards. I had just painted the walls with BM Aura and hadn't planned to paint the baseboards. But, when my walls looked fresh, I noticed the baseboards looks pretty bad. I used the Behr to freshen them up. It went on fine, in fact, I liked it better than BM Satin Impervo. It's only been a year, so they still look good. I wasn't too worried about the Behr as we are planning to replace the skimpy baseboards when we get new floors, hopefully this year.

For trim:

I REALLY like Cabinet Coat. It can be harder to find. Their online site was pretty worthless. You might need to call around and even then, I found out that sometimes people on the phone don't know they carry it. I found it at Ace, which is further away, but I also found it at Kwal, who told me on the phone they DIDN'T carry it, and now my local mom & pop hardware store carries it. Elliots in Dallas area if you're near here. It dries smooth and silky like an oil base and no brush strokes. There's a learning curve, learning how to apply it without it sagging, but the results are amazing.

Ace Cabinet, Trim and Door. Again, Faron is the go-to guy to ask. I've never used it as Ace is 15 miles away whereas Elliots, my Cabinet Coat supplier is only 5 miles.

Benjamin Moore Satin Impervo. For trim, doors, baseboards. I didn't like it very much, although many people swear by it. I got a lot of brushstrokes. I should probably have used XIM Extender, but I didn't know that at the time.

I'll post a great like for "10 Tips for a Perfect Paint Job" by The Family Handyman magazine. The instructions with pictures came out in their magazine a few years ago, but the website has the same info.

Sooo, google map your address and then click the Search Nearby link on the left column. Type in paint store and a list of stores near you will come up. You might be surprised at what you find, I know I was.

Good Luck and Happy Painting!

Here is a link that might be useful: 10 Tips for a Perfect Paint Job

Yeah, unfortunately, C2 lost some stores...gained others. Slippery economy ya know!
I dearly love the paint itself though, as do increasing #'s of people up here!

FPE-
Yeah, you PAY for it...but it's DAMNED amazing stuff. Unreal actually! Consider it for special projects maybe. The glosses are just sick!

Cabinet-Coat-
Good stuff obviously! Any ACE can get it. Casepak is 2 gallons or 4 Qts. Some small stores may not want to stock it if they don't think they have a market for it.

Yeah...ACE-Royal is our bread-&-butter. VERY good paint in its price-point. 100% Acrylic. The premium "Royal Finest" has the Scotchguard in it. Around $32/gal. Used to be called "Flat Sensations, Satin Sensations, etc.)

>>> We're kind of a "Renegade" ACE! We've had C2 as our premium line, and we're NOT changing it! Ralph-Lauren is very popular here too. I like it a lot. Very good paint by Akzo-Nobel/formerly ICI. One of their premium lines.

Faron