this is the textbook i used in my AI class:
Norvig and Russell - Artificial Intelligence, A Modern Approach, 2nd edition, Prentice Hall, 2003
also you may want to look up info on some similar/related subjects:
genetic programming, simulated annealing
this page looks like it has a somewhat simple explanation on how to create a genetic algorithm.
also if you want, pm me your email address and i can send you the sample code that my professor gave us for a simple genetic algorithm.