You get all the drivers provided if you use 32bit XP or Vista.
When you turn your Mac on you hold down the option key to select Windows or Mac, or you can let it load the default OS you choose.
It runs like it's Windows in a pretty shell! That means getting Anti-Virus software etc.
You can read files from the Windows partition on Mac but cannot write, although you can copy the files across. With work arounds, such as NTFS-3G, you are able to read/write on the partition, and with software, such as MacDrive or TransMac, on Windows you can read/write to your Mac partition.
Games will run in Parallels but it'll be sharing the RAM with OS X and all in all i find it to be a lot lot slower. I suggest using bootcamp, which supplies the drivers when you start the install (and asks you to burn them to disc or save them to USB pen, from the menu).
Need more? Feel free to ask!