Thanks for your question! There are a few places I would begin. One is a book called Lesbian and Gay Voices, which is a bibliography of books for children & young adults. This link will show you the nearest libraries that have it: http://worldcat.org/oclc/43323679&referer=brief_results

Ditto for The Teen Reader's Advisor, which is more mainstream but appears to have a broad outlook. Chapter 14, for example, has these sections:
Chapter 14. Love, Sex, and Romance
A/ Classic Love, Sex, and Romance
A/ Bisexual/ Transgendered/ Questioning Teens
A/ Dating/ Crush
A/ Dating Violence/Rape
A/ First Love
A/ Gay Guys
A/ Lesbian Girls
A/ Unplanned Pregnancy/Abortion
B/ Resources: Additional Romance
See libraries that have it at http://worldcat.org/oclc/67383774&referer=brief_results

An online bibliography, while not geared toward the love/sex realm, is at http://www.marxists.org/subject/art/literature/children/bib/index.htm

I hope this is helpful. Please let us know how we can assist you further!