Php

When I began learning PHP (believe me, you're never finished), I started with this tutorial, and it set a really good basis for learning PHP. W3Schools also has a great tutorial and reference page for PHP as well. From there I basically just do some investigating each time I need to do something in PHP.

Also, don't forget php.net. I always go there when I need to look up a function or class.

The link to Tizag tutorials mscreashuns posted is one of the best places to start.

It doesn't go into complicated detail or the expert side of things, and that's exactly how you want it when you first learn.

When your knowledge advances, you'll often find Tizag wont provide enough details, and that's where php.net comes in, as pr0gr4mm3r mentioned.
PHP.net goes into more detail about PHP usage. Instead of a simple "this does this" it list all relavant information about usages, limitations, depreciations and more demanding/complex examples etc.

The best way to learn I think is when you actually have something specific to do, rather than just reading tutorials.
Perhaps set yourself the challenge of writing something particular, like a simple membership registration and login script.

If you visit Hotscripts then you can find all kinds of codes there, from Javascript to PHP.