i second that - i got the 2nd ed of that years ago and it is one of the few computer books in my large collection that is very well thumbed to say the least! i found it fantastic, and as well as explaining all the theory very clearly, there are several common sample applications (shop, login etc) gone through at the back...

only issue is that the 3rd ed was out in 2004 and the 4th ed is out in august Amazon.co.uk: PHP and MySQL Web Development: Books: Luke Welling,Laura Thomson
so i don't know if you can wait for that

as uncle said, the docs at php.net are excellent and you can search and get to each function/section really quickly there. once you find your feet, that's the main reference really...

good luck!