I know this is an old post, but just in case you are still here.
PHP is not a big leap. In my opinion
www.php.net has the best help I've ever seen for learning the language. There are plenty of examples for you to use and get a feel for how everything works.
Javascript may be a tad harder to pick up, but again you can find plenty of examples to learn from. Do a search for prototype.js and you can pick up some simple AJAX skills and add that nice buzzword to your list. Also search for scriptaculous and play with those examples.
I think the best way to get into web development would be to start with building your own webpage. Design something that lets you show off all your new skills. For me, I learn best by taking small examples and building up from there. Good luck getting started!
Ryan
www.teratomic.com