For basics you can go to this cool site:
PHP Video Tutorials - Learn PHP the easy way! PHP: Hypertext Preprocessor is, the best, check there when you need any info.
Once you got the basics, just look around on google for tutorials to help you build a blog, then you can move on to a content managment system, then a forum, then maybe a shopping cart adding features as you go along (e.g. add comments to your application or ratings, or user profiles/control panels etc etc.. Till you get comfortable with making applications, then if you want, you can go and do some more advanced stuff with it.
I'm saying this, but I'm still learning it myself. lol