Wanna link here?
Willow/Tara - Can't you guess?
Wiccan Ways - Great site with an index of all the W/T fanfic around.
The Pinkrabbit Consortium - Some of the best fic on the net.
Between the Sheets - Has tons of fanfic and also some great pics of MKF (from The Yoko Factor) as well as the infamous "you have a catnip problem" scene. Check it out :-)
Sunnydale High - The great site where (almost) all the pics on this site come from :-)
Beneath the Bronze - Really cool Buffy site.
General Buffy Links
Sonja Marie's Buffy the Vampire Slayer Links
Buffy.com - The official site.