So, you want to learn how to build websites using php? It's a topic that's come up in several of my circles in the past few months. One fellow developer wanting to broaden his skill set, another entrepreneur that's just not satisfied letting someone else build his project out (and rightfully so) and another college age individual that just wasn't sure what they want to do "when they grow up." "You should", is what I tell them, and it's what I'll tell you too. You should learn php. You should learn css. You should learn to build a basic html structure page. You should familiarize yourself with xml. You should learn about mysql databases and the beauty and danger of javascript.
Everyone should learn at least the basics of what powers a website. The reason I feel so strongly about this is simple, it's the same reason you should know how to change a tire. We all use the internet these days, so it would be very helpful for you to at least know what's driving the sites you're interacting with on a daily basis. Most people don't know the difference between client side and server side, and it probably doesn't matter to them - but they are also the ones that will think Youtube is broken rather than realize that they just need to stop using Internet Explorer or update their flash plugin.
This really wasn't meant to be a rant, just my bit of encouragement and reasoning for advising everyone I know to at least go try out a "Hello World" tutorial. The absolute worst thing that could happen is that you might surprise yourself and learn something, or not... then you're right where you started.