Three books on genes and heredity, starting with:
Towards an Understanding of the Mechanism of Heredity, by H.L. K. Whitehouse (hardcover , 1969, $ 3)- the most technical of the books, and the oldest.
The Human Blueprint, The Race to Unlock the Secrets of our Genetic Script, by Robert Shapiro (trade PB, 1991, $3)-written for nonscientific readers as well as the scientifically inclined.
Quest for Perfection, the Drive to Breed Better Human Beings, by Gina Maranto, ( hardcover, 1996, $3)- the newest, and the one to read while you ponder the possible consequences of "society's attempts to control human destiny by regulating birth outcomes".
Look for them in the biology section.