[For the most part, these sites are selected by the staff of The Cauldron: A Pagan Forum or suggested by forum members. We used to have a form for the webmasters of Pagan sites to suggest their site and do link exchanges but it got to the point where we were getting 15-20 spam requests for every actual Pagan site (and the Pagan sites were getting lost in all that spam), so we reluctantly dropped this feature.]
Isaac's home page is full of information and essays of Paganism and Pagan Issues. There is
a lot of information here and almost all of it is worth a look.
Yasmine Galenorn, author of Embracing The Moon and others, has an interesting web site.
The author of one of the most influential books on Wicca, Spiral Dance, now maintains an interesting page on the web.