PHP:

http://www.slashdot.org
News for nerds. Lots of info here, but not that much in the way of code. Mucho links to code though.

http://www.zend.com/manual
PHP comes from here. Good stuff. www.php.net/manual/en is also good, maybe better cus it has some additional comments and code snippets.

http://sourceforge.net/
You can't go wrong with stuff from here. Sourceforge is way powerful.

http://www.freshmeat.net/
Freshmeat has tons of open-source software. Indispensible.

http://www.weberdev.com/
Pretty nice site. Lots of specific code for PHP MySql usage. You used to have to register, which was kind of a bummer. Now it's free.

http://hotwired.lycos.com/webmonkey/programming/php/index.html

http://code.box.sk/

http://www.phpbuilder.com
Excellent site. Tons of goodies and easy to use.

SQL:
Here are some nice sql resources:

http://w3.one.net/-jhoffman/sqltut.htm
Very basic tutorial, but it's been up for ages and has some good generic stuff in it.

http://www.sqlcourse.com/
This is good. Lets you run sql commands on the fly and see results right on a web page.

MySQL:
MySQL is a GNU licensed database. It's my personal choice:

http://www.mysql.com/