H5X, I got this wifi adapter from ebay:
I set up the Pi with a LAN cable and then plugged in the wifi adapter afterwards. This is my first Pi and I set it up about 6 hours ago. I connected the wifi adapter to my network - it just worked. No need to load any drivers. After setting up the Pi it is sat plugged into the TV but I have been accessing it via SSH. I plan to use this as a media centre although I am planning to have a play around and see how a bit torrent client works.
I would suggest a powered USB hub also (once you start thinking about it there are plenty of extras - power supply, HDMI cable, USB storage if required). And a couple of SD cards won't do any harm. That way you can set up a few different distros.
And agreeing with the 'gong, raspian is perfect.