This book provides a good enough grounding in the principles behind Genetic Programming to begin to use the techniques discussed in projects. The text is very accessible and well backed up with references and further reading. Even though this book is available as a free download, purchasing the hard copy is well worth it. One word of caution: this book explains the principles and ideas behind GP very well, but what it does not do is hold your hand in a step by step implementation. That said, given moderate coding ability the provided source code of TinyGP provides an excellent starting point.