Two key questions for those first exploring GP are:
The best way to begin is obviously by reading this book, so you're off to a good start. We included a wide variety of references to help guide people through at least some of the literature. No single work, however, could claim to be completely comprehensive. Thus Appendix A reviews a whole host of books, videos, journals, conferences, and on-line sources (including several freely available GP systems) that should be of assistance.
We strongly encourage doing GP as well as reading about it; the dynamics of evolutionary algorithms are complex, and the experience of tracing through runs is invaluable. In Appendix B we provide the full Java implementation of Riccardo's TinyGP system.