Hi there, "Jon N/A". Glad to see you here.
If you want to learn some HTML, CSS and PHP I can recommend the basic tutorials on W3Schools. PHP's official homepage is also excellent if you want to search for a specific function. Complete with descriptions and code examples.
Be sure to check the Java API whenever wanting to know about Java functionality (though I don't know of any good beginner's tutorials).
[personal opinion]When it comes to Flash, I actually find Adobe Flash to be quite horrible (for making games, it's ok for animation and smaller stuff). I've lately been checking out Flixel and FlashPunk in a FlashDevelop environment and I very much prefer it. Bonus: Contrary to Adobe Flash, it's all free.[/personal opinion]