The most important thing is to understand your learning style and then exploit that. Take a class? Read a book? Dive right in? Reverse engineer? Teach? Only you can answer that question.
Have fun!
MySQL functions = bad, PDO = good
die() = bad, throw new exception = good
$_GLOBALS = bad, bad and more bad
quoted SQL = bad, prepared statements = good (do not trust mysql_escape_string or any variant of it)
striptags() = bad, HTMLPurifier = good
And finally, for the confidence you need to start a project that's a little scary:
every other programmer = bad, you = damn good
Good luck! :)
[edited for spacing]
http://devzone.zend.com/article/627
Also if you are interested in Zend Framework and want to master Zend Studio quickly, the e-book "Zend Studio for Eclipse Developer's Guide" by Peter MacIntyre and Ian Morse is very good.