I'd recommend buying the SAMS Teach yourself PHP in 24 hours book. I think its on amazon.com somewhere but i bought my copy from a book store...
So far i'm at the image manipulation in PHP chapter because i stopped reading it before my exams but its a fantastic book. Only thing i didn't like so far was the chapter on Object-Orientated programming but there's still plenty of time. It's simple yet goes into a lot of detail.
Also you have to keep coding and coding whilst your reading the book as there's nothing better than hands on practice

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Excellent buy!
- miSt