I started learning PHP this summer, and I found the best way to learn was to set your self a challenge of making a website. Basically write down a list of features that you want on the website and work through each feature finding out how to do it as you go along by looking it up on various websites/tutorials, then move onto the next feature.
For example; I created a online shopping website. So I had to find out how to have a cart/checkout system, a login for a user/admin, a contact form, that kind of thing. Once I went through each feature and completed it I learned abit more each time, and after about a month or so I was fully int he swing of things.
It could work for you, so it's just a suggestion.