40K Online, Tau Tactica, Spacemap

Here are some of the sites i frequent.

For all your army q&a, lists and tactics i have found the 40konline forums to be very good.
http://www.40konline.com/

Arguably one of the most professional sites out there for all you Tau fans. If you are going to join this one make sure you read all the rules, they kick people all the time.
http://www.advancedtautactica.com/

This is a site originally posted by Quinton(spelling?) Amazing star map of the 40k universe.
http://www.joachim-adomeit.de/wh40k/spacemap/map.html