If you look at this list of Lambda Literary Award Finalists and are appalled by how few of them you've read, you are not alone. I've read The Big Bang Symphony (oh, so good) and Just Kids, and that's it.
This must be rectified. For me, since I hope one day to be listed in the category, Lesbian Debut Fiction is a good place to start. My choices are Alcetis by Katherine Beutner, Fall Asleep Forgetting by Georgeann Packard, The More I Owe You by Michael Sledge, One More Stop by Lois Walden, or Sub Rosa by Amber Dawn.
P.S. One of these novels, it seems, is by a man, Michael Sledge. Now I'm sure it's a lovely piece of fiction, but I thought the purpose of a Lesbian Debut Category was to support and promote lesbian writers.