I have both Bootcamp & Parallels on a iMac & MacBook, depending what your plans are depends which one is best really,
Bootcamp, is just like running a Windows based machine, no differences at all. Haven't found any issues with XP (haven't tried it with Vista, as don't like that OS System). When logged in through Bootcamp, it uses all the system to run this, so get better speeds etc, great for gaming.
Parallels also is good, as can run both OS's at same time, so if you need to quickly do something in windows, but don't want to reboot the Mac. Bear in mind, the system is being used to run both OS's then, haven't really noticed much in this, but then only use Parallels for quick things, like updating the Sat Nav etc.
So basically if using Bootcamp (which is included free in all new Macs now), I haven't found anything I cannot do yet - that a Windows can.
Any USB mouse with 2 click buttons will work on both OSX & Windows too! - I know in OSX you can press control and click for right click, but this doesn't work for windows though. - OSX Also allows for 2 mouse clicking.
The Apple Stores don't actually support Windows (Bootcamp or Parallels), if you have any issues, and will say contact Parallels or Microsoft for assistant, depending on the programme using. - Unless you find a kind person at a Genius Bar, who knows enough about Windows and is willing to help.
Bear in mind, that you'll also need a copy of Windows & a code to install