This is a compendium of translations of over 20 classic Chinese texts on Taoist esoteric sexual practice. For those with this particular interest, I highly recommend it. There's no other book like it.
This is not a 'new-age relationships' book, nor a 'light-reading sex-tips' book; it's a scholarly and faithful set of translations of Taoist texts originating from the second century B.C. through the early 1700's.
These might be rather heady for the beginner, but if you've studied alchemical Taoism (especially the sexual aspect) from more modern sources - and would like to peruse some of the classics (from the 1000's of years that the Chinese have been studying this stuff), then this is THE book. It's extremely well written; the introduction alone is worth the price of the book.