Wix: Why it sucks.

Oh sorry @Natsu I thought I had replied to this, but I guess I forgot to hit "post reply" or something.

If you're doing the whole HTML/CSS/JavaScript thing, you're very much off to a great start. That's all client-side coding, which means that you don't need a server in order to view it because the processing is done in the browser. On the other hand, PHP is server-side scripting, and it requires a server for processing. It's definitely a good thing to learn (even though I don't care much for the language) because the vast majority of all web pages online use PHP.

jQuery is a JavaScript library--if you know JavaScript, jQuery isn't too difficult at all. Because it's a JS library, it's client-side too. This would also be a very good thing to learn. So, if you're trying to decide between jQuery and PHP, my answer is "learn both!" Learn PHP first if you want to work with the back-end more, and learn jQuery first if you want to do some really cool things with the front-end.

Another thing that you might not have considered yet is looking into programming languages like Java. (Note that JavaScript and Java are not the same language.) Java is generally used to build applications, but it's also used for building servers. MeepCraft, for instance, is running on Java-based server software, and Minecraft itself is Java. In the grand scheme of all programming languages, Java isn't too terribly difficult once you get the hang of the object oriented paradigm.

Let me know what you'd like to start working with, and I'm sure that I can dig up some resources for you.