Sexing the Brain is a semi-academic book written by Dr. Lesley Rogers, a professor of biology in Australia. The book consists of a series of essays about what role, if any, genes and sex hormones play in sexual behavior, and in general cognition.
Put briefly, Dr. Rogers answer is that they play little role in sexual behavior and almost none in cognition. The main thrust of her argument, however, is not placed entirely on scientific ground, but rather on examining the political and social biases of groups claiming there is a gay gene, as well as methodical critiques of many experiments. For example, she points out that a statement that the brains of homosexuals are of a different size in certain areas is based on a sample size of around a dozen brains, and that these brains were taken from the cadavers of AIDS patients, and that extrapolating this result to "homosexuals" in general is rather far fetched. Quite a bit of the book is taken up with dissecting the methodology and presumptions of such studies.
She also, later on, takes shots at the Central Dogma itself, pointing out that genes are greatly influenced by the environment and that very small shifts in the environment early on can change brain structures radically.
This book is not technically in depth, at least in the ways I am used to. There are not any brightly colored diagrams showing how neurotransmitter A activates protein A, wheras neurotrasmitter B does not. In fact, very little of the book gets into the details of brain function, let alone chemical diagrams. Of course, since the book is only a 100 pages long, there is really not room for such things. Also, this book seems to have a somewhat polemical tone, with the author making the same point many times. I tend to agree with the author, which makes the polemic somewhat easier to digest. A person with different thoughts may get tired of the book, however.