Yes...it should have two contacts for the power. I'm assuming you know about correct loop direction. If the only wires in the box are the two for the switch, and you're certain which breaker is involved, you don't need to shut off the house main. On the other hand, since your skills sound basic, if you aren't absolutely sure about which is the correct breaker, or there are other wires in the box, you may be safer turning off the main.

I replaced the toggle switches in my kitchen with push buttons from Rejuvenation House Parts. They are period authentic and work beautifully.

If you panel is decent I can't see the need to shut down the main power supply to the home. The breaker controlling that switch should be just fine. Of course, with old homes and old panels, there could be issues you don't know about! That's why I just replaced mine. Now I feel comfortable working with the circuits in my old house.

Here is a link that might be useful: Rejuvenation's switches

We got our push button switches from classicaccents.net (same switches as Rejuvenation, but cheaper:)). Our electric service had been upgraded so we had no problems. Now, if we could only get LED bulbs to work with push button dimmer switches properly....

Thanks all! I think it will wind up being an easy project based upon other toggle switches I've had to replace (with other toggles) in the house. I just wanted to make sure I wasn't going to run into any major issues (which of course I still can). There are only two switches, each controlling one light, one with a dimmer. Of course now I have to switch out all the plastic plug covers with brass ones (however more fun than simply replacing the broken dimmer with another toggle dimmer).

I've heard some complaints about Classic Accents switches -- cheaply made, wobbly buttons, hit and miss quality, too many failures, but I don't have any first hand experience with them.

House of Antique Hardware also offers them. Friends of mine bought several to replace failed ones in their home, and they were very happy with them.

I bought two for Mom's house to replace two that had failed. They really look, feel, and sound like the originals.

I have used the CA switches, and they are a bit cheaper than Rejuvenation...but I read somewhere that they actually come from the same manufacturer.
My replacement was for the original button switch to the basement--did it about five years ago, and it still works fine. I will say, that their 'click' sound isn't as loud as the original, but at least it looks the same. Incidentally, my original switches are in porcelain boxes--smaller than modern ones, but a total surprise to me when I changed it out.

Light switches are an easy change out as long as you have a good understanding of electricity and a healthy respect for it. I would, although, recommend getting a good "Multi-meter" and learn how to use it properly. Our house was built in 1882 and, as far as I can tell, the electric was added some time in the 1920's. Some updates were done over the years by PO's, not all necessarily done correctly. I've found a couple of instances where one of the PO's switched the polarity when hooking up part of the circuit so that the white wire, which should be the "Common" or "Neutral", was the "Hot" side. Not all the wiring was done this way, just enough to make things interesting.

What I'm trying to say is test everything before you grab onto it. Don't take it for granted that it was done properly by the last person.

We've got about 20 Classic Accent push button switches and have had all for about 5 years. None wobble, none have broken, none have failed. At the time we bought them, their customer service was awesome! No regrets with them at all.