Hop over to
Script School and take TDavid's 16 part (you set the pace) course on PHP. That's where I started learning PHP and now it's what I do for my living. The course if free and full of information on most if not all of the questions you have.
Then hop over to amazon.com and grab a copy of this book:
PHP Functions Essential Reference by Greant, Merral, Wilson & Michlitsch; published by New Riders. It's a great reference manual and is organized a bit more logically than the php.net manuals. I've had my copy for about 6 months now and I'm probably going to have to get a new copy of it by year's end because I've used and abused it so much.
