Oli on “What’s next?”
I'm going to echo JulianBH. I'd leave the sever-side stuff alone until you're more than just acquainted with webdesign.
I think Mike's quite wrong in saying you can't build anything without a server side language. Sure you can make web apps with them but I think it's more important to find your focus...
Ultimately, everybody falls under one of two labels: designer or developer. One can do the other's job but most people find it easy to tell what they enjoy doing the most.
Therefore, I think it's important that you give one a thorough go before you consider moving on. PHP (et al) rely on your presentation skills so much that I think you need to know what you're doing there before you take it up.
So what does that mean to do? Making mock-ups really.If you can make sexy mocks, you can make sexy templates. If you can make the templates, you can use them in PHP. If you can use them in PHP, you'll have an absolutely awesome time developing things.