Remodel 101, get everything in writing before work starts.

Biggest thing that I have found is miscommunication. the trade hears 1 thing, you meant another, something gets left out and is an "extra" later.

sometimes the cheapest guy is the best, but most of the time if there is a guy who is significantly cheaper it is b/c he either missed something, is missleading you, or doesn't deliver as good a job.

I am sorry this has all happened at once for you. I know it can be overwhelming. LAst year, in the midst of our kitchen/LR/DR remodel, we discovered a huge mold problem that necessitated gutting the master bat area and another huge unplanned-for renovation project. It can be really stressful! I sounds like you're not living in the house while this is going on, so that is good.

But I also just want to warn you that being your own GC is no picnic. We're very experienced DIY-ers and my husband is a boatbuilder so he's used to dealing with very similar issues, and we've both owned small businesses.... so you'd think we'd be the ideal people to be our own GC. But it's a LOT of work, and it's STRESSFUL. And- when things fall apart, as they inevitably will in a remodel, you've only yourself to blame.

It makes me nervous that you're taking this on, and then asking us for Remodel 101 advice, I hope it won't overwhelm you.

I'd first get some books out of the library or buy some from Lowes or Borders or something. There are several about how to be your own CG, and/or how to plan and organize a major remodel (look at the "house building" ones as well, which will cover many of the same issues). There are sooooo many things you need to know, from scheduling and contractual issues to the nitty gritty of the jobs themselves, I hope you will read up before plunging in.

And then, check out the other boards on here. Some very active ones that should benefit you are:
Kitchens
Baths
Home Decorating (which also includes remodeling issues.)

There are pros on those boards who very kindly share their experience and advice, plus folks who are just obsessed/immersed in the topics who have great ideas, too. And support, when you need it.

In my experience as my own CG, I found that I did save a tremendous amount of money by doing a ridiculous amount of online research on materials, and getting, for example, a $500 faucet for $85 or whatever... rather than simply letting a plumber say, "You should install Kohler faucets. Go pick what you like at the showroom and I will order it for you." (And he adds a markup over the already higher local price.) But the stress of having to oversee every little thing and make major decisions about things you're only nominally educated about is pretty nasty.

Good luck!