scriptygoddessSince I've been learning so much PHP over the last 3 or 4 months, I've been collecting a lot of bookmarks to help me out. Althought PHP.net is the most helpful of them to me, I've gotten a great array of other links in my bookmark files too. Most of these are aimed at people just starting out with PHP (or still a bit of a newbie needing a tutorial to learn more).
If you'd like to learn how to include files and show the current date, and maybe just see what else PHP does, these links are for you. If you are already doing that stuff and want to get more advanced, then you might check out HotScripts and The PHP Resource Index – download some scripts and pick them apart until you understand what they do! 
And if you are looking for a good editor for your PHP, I tend to use EditPadLite most of the time (mainly because I can open multiple files and it has a line counter which is helpful for debugging), but Zalary linked to PHP Coder Pro the other day, so I'm trying that out and really like that it color codes my syntax – easier to see when you miss a comma or quote!
Feel free to add your favorite links in the comments, too!
- PHP.net
Ultimate reference manual, where you can search for any function and find out how the information should be formatted. If every programming language had this complete of a manual, I'd be so happy! - PHP Basics
Excellent beginning article. Gives an overview of all of the basics you'll need to start coding. - PHP Complete: the newbienetwork
A great selection of tutorials – I like this one because they separate out the information into good categories, making it easier to find stuff. They also have a forum that you can ask your questions on. - Frequently Asked questions – PHP
I've found when I'm searching for something specific (like an error message or function idea), this search engine usually finds me something. - CNet's Intro to PHP
A pretty complete beginning guide. May be more aimed towards people already code-friendly. - And even more info is here – this is a good place to get more links: WebsiteTips's PHP index
