PHP is a simple language, to be honest once the basics are learnt the only place to be is the Manual.
However ive read a small portion when someone wanted me to recommend a book.
Build Your Own Database Driven Website Using PHP & MySQL - By Kevin Yank, is quite good and still a popular read.
You may wanna read the latest book for PHP thats there, http://www.sitepoint.com/books/ they havent made many but they have had very good quality books. There latest by Harry Fuecks is extremely popular at the moment (more aimed at the intermediate/advanced user)