Here's a good source:
Informing Tomorrow's Revolution

Also, for GLBT fiction & nonfiction for adults including young adults, see
Stonewall Book Awards

Followup:

I think the first link came from the Library Underground listserv.

The second is from the American Library Association's website, which has tons of bibliographies available. See also their page on young adult books:
YALSA

Second Followup:

I subscribe to listservs like the Underground Librarian in order to keep up with items of interest like small-press & underground publishing for young adults, etc. I recommend that you subscribe as well, and also seek out other similar listservs. Here's a sampling:
Diversity-Related Library Listservs

Also, this one might be of interest to you:
YO-LIBA Discussion among youth services librarians. To subscribe, send the message "sub YO-LIB your name" to listserv@listserv.kent.edu
You can certainly find others via Google, just by including the word "listservs" or the phrase "discussion lists" in your search. Add other relevant terms as well, depending on the teens' interests and backgrounds.