Since we have the gay boy list and the lesbian list, here's my transgender list. These are the non-fiction transgender-relevant books that have meant the most to me personally, but I know there are others which should be on this list, so please add your own choices in the comments!
(H/T to Michael Crawford for the suggestion).
1. True Selves - Widely considered THE book on the topic, this is the book my therapist insisted I buy and read the day I came out to her, and once I had, it was easy to understand why she did. If you've got questions about transsexuality or know someone who does, this book is an absolute must-read.
2. Transgender Warriors - A true classic. Leslie Feinberg's history of transgender expression will teach you that not only aren't transgender identity and expression new things, as some like to believe, but transgender people have a history as long and as rich as any other subgroup of humanity. If you're simply looking to learn more about transpeople and our place in history, you will get that in spades. If you're trans, you'll also get something else: The understanding that you, as a transperson, are a part of something not only far greater than yourself and the community we know today, but also an heir to a rich and vibrant cultural history, that you are not, and never have been, alone in the world. I read this at a time when I was very depressed and looking for answers, and I don't think it's an exaggeration to say reading this book probably saved my life.
3. Read My Lips: Sexual Subversion and the End of Gender - Riki Wilchins' first book is an awesome read, particularly of you are newly-out transperson wanting to learn more about where you stand socially and politically. Although originally published 10 years ago, much of this book remains strikingly relevant today. If you're looking to become an activist and help make the world better for gender-variant people, or even if you already are and want to be a better one, you need to read this book.
4. How Sex Changed: A History of Transsexuality in the United States - A deeper examination of the modern history of transsexuals in America than found in "Transgender Warriors", this book explores the development of the modern American transgender community and culture through Christine Jorgensen, Dr. Harry Benjamin, and how transsexuals have fit into American society and culture over the last half-century.
5. The Transsexual Empire: The Making of the She-Male - Wanna get pissed off? What to know what some so-called "feminists" really think about us? Then this is a must-read. Janice Raymond contends that transsexual women are really men trying to invade women's space to enforce their vision of a patriarchal system upon women. No, really, I'm not kidding. And female-to-male transsexuals? They don't really exist, they're all really lesbians in denial. As nutty as this sounds, this book did considerable damage to the political and social acceptance of transsexuals when it was published. Raymond's "research" is credited with being largely responsible for Johns Hopkins University shutting down its gender identity program in the early 80's and is still cited today by those in opposition to transgender equality and acceptance.
6. Queer Theory, Gender Theory: An Instant Primer - This one is fairly heavy stuff but a good read. Riki Wilchins deftly blends postmodern gender theory with illustrative examples from hir own life and from LGBT and transgender social and political history to make these concepts accessible to the average reader. By no means an easy or casual read, it's well worth the effort.
7. Gender Outlaw - Kate Bornstein has to be the most entertaining writer ever to take on the topic of gender. Bornstein is all at once funny, thoughtful, incisive, provocative, and most definitely thought-provoking. This one is a true classic, and for damn good reason. If you're exploring your gender or would like to, you won't be able to put it down.
8. Trans Liberation: Beyond Pink and Blue - This is a collection of speeches and articles by Leslie Feinberg, in which ze defines hir own perception of gender identity and expression and hir vision of the future for transpeople. Also included are the words and short portraits of community icons such as Craig Hickman, Sylvia Rivera, and RuPaul. While those familiar with Feinberg's other works may find some of this familiar, it's an excellent overview of hir vision of our community and our place in the world.
9. My Gender Workbook: How to Become a Real Man, a Real Woman, the Real You, or Something Else Entirely - Another fun romp through the wilds of gender with Kate Bornstein. Just as engaging and entertaining as her first, "Gender Outlaw", this book is indeed a workbook, not only offering more great reading but also exercises which the reader can do to further their exploration of their own gender. No matter of you've been questioning your gender for ten minutes or ten years, this one will really make you think.
10. Becoming a Visible Man - Part autobiography, part social and political exploration of transgender and particularly female-to-male transsexual identity, and part call for transpeople to live openly, honestly, and passionately, this book by transactivist and educator Jamison Green is an excellent read for anyone, and an especially good choice for FTM transmen looking for something that speaks directly to them and about their lives.