So, the Boot Camp process can be somewhat tricky if you miss the part where it prompts you to print the manual. Assuming you did miss it, now might be a good time to catch up:
Boot Camp Manual (download)
It covers two important pieces - the first being, how to choose which OS you want to boot into. This is done by holding down the Option key as soon as you turn the machine on. From there, you can choose either "Macintosh HD" or "Boot Camp".
The second part is how to install the Boot Camp support software for Windows, which installs the needed drivers, as well as special software to make using Windows on your Apple hardware more seamless. This software is actually bundled right with your Snow Leopard (or System Disc 1) disc. You'll want to boot into Windows and insert the disc. You should then be able to install the software within Windows.
When it's all done, be sure to run Apple Software Update (from within Windows) in order to get the latest driver versions.