Ye' old general discussion board. Basically, for everything that isn't covered elsewhere. Come here to shoot the breeze, shoot your mouth off, or whatever suits your fancy. This forum is not for asking programming related questions.
The first book I bought so that i could learn some basics was "Sams Teach Yourself PHP4 In 24 Hours." That's a pretty good newbie book. Now I'm on reading "Wrox Proffesional PHP4." Wrox got some awesome books.
But I have agree that error messages is grat learning. Even if they get so irritated some times that I just want to throw the computer out of the window
Started with PHP Developer's Cookbook, PHP and MySQL Web Development books. Now I tend to really only use the manual and if the internet's being a bit slow, Programming PHP by O'Reilly. This forum's great for learning new ways of doing things too.
I started with messing with other peoples coding to fix the html they used, then i just used the manual to look functions up...
I bought a book by Wrox, it is really nice... but by the time i bought it, it tought me more about HTTP and GET and POST and TCP/IP and the like than PHP...
Core PHP Programming was my first book...after that, well, I just started buying books like crazy.
My personal favorites right now are two non-PHP books, one by Steven Krug called "Don't Make Me Think", and the other a wonderful CSS book by Eric Meyer, aptly titled "Eric Meyer on CSS".
Books: PHP4 Bible from IDX Press was my introduction, I still find it useful Advanced PHP for the WWW Visual QuickPro Guide, was good for learning image/pdf manipulation Prof. PHP from Wrox another good advanced book and of course the PHP O'Reilly book and The Manual.
(of course supplemented by various sql, PostGreSQL, and html books)
Tutorials: Jason's companion site is wonderful; phpBuilder is great too.
Classes: (not PHP specific, but ones that will stand anyone in good steed)
Introduction to Computer Science (text book: Structure and Interpretation of Computer Science aka SICP, MIT Press, absolutely wonderful for teaching the basics of computer science)
Introduction to Algorithms(text: Introduction to Algorithms by Cormen, Leiserson, and Rivest (2nd Ed with Stein also) aka "The CLR(S) book")
Software Engineering (we used a preprint text...)
To me those three classes form the foundation for any further work on large projects.
I just read other peoples code, edit it, get a load of errors and then scream for help, then I use #php @openprojects or the manual, some clever friends are also handy to help solve problems.