Archive of Our Own : The Garak/Bashir tag of this multi-fandom archive is a great place to find stuff.
Trekiverse : The archive for the alt.startrek.creative* newsgroup hierarchy.
Doctor, Tailor (LiveJournal) : If you have a LiveJournal, check out this community for fans of Garak/Bashir slash and friendship.
Doctor, Tailor (Dreamwidth) : And if you have a Dreamwidth journal, you can join this parallel community!
Cardassia Sutra : An extensive G/B-specific archive. Many authors, many wonderful stories. No longer updated, but a wonderful source of older G/B.
The Garak/Bashir Fuh-q Fest : Stories and art from all eight rounds of this retired fest.
Kinky Corner : A list of kinky story links for all Trek series. Satisfy all your kinky Trek cravings!
Elizabeth Helena's Stories : All of Elizabeth Helena's excellent DS9 stories, including her Top Ten Lists. She's one of my favorite writers, so check her out!
Fred, Lover of Wesley's A** : Ah, Fred, master of squick! :0) No longer updated.
Diana and Joanne's Slash Sensation : Longfic AU from back when longfic AU was very rare! No longer updated.
Sid City : Alexander Siddig's offical fan site has been serving his fandom with consistent excellence for as long as I can remember. Decades, at this point! Project news, photos, and videos.
Andrew Jordt Robinson : An unofficial fan site for Andy Robinson. Lots of great content on this newer and growing site! Photos galleries, video links, links to online interviews, and content submitted by other fans such as fan art, photos, and fan encounters.