The ebooks below I used when I first got started. Whilst they relate primarily to Google Adwords the principles are basically the same for other ppc programmes.I also read every article & forum I could find on the subject(there is a wealth of knowledge to be gained in these forums that many of the posters very generously share).
Remember also to check that material you read is up to date as the internet is constantly evolving (particularly at Google).
The Definitive Guide to Google Adwords By Perry Marshall is the most comprehensive I've seen. Google Cash By Chris Carpenter Is one of the most popular & the one that got me started. Google Profits By Wade M. Winger is also an easy read & a good basic starters guide.