I definitely recommend starting/joining a big project, its the best way to learn, no question about it. I myself learned almost everything i know now from the project Im working on atm, and I tend to only use other resources as references, rather then outright learning from them. It's difficult to come up with a website project big enough to encompass all the skills you will need to develop, but if you keep thinking on it, im sure you'll think of something.
Once you come up with your big idea, spend time researching how your going to make it a reality. It's perfectly fine to use references often, because eventually youll memorize how to solve the problems you keep running into. Personally, I dont really like visiting one website and learning only from there, i think its better to just use google, and determine what resources click the best for you from the results you get, and maybe some sites are better in different areas. A lot of times results from stack overflow will show up, and the answers can be really helpful.
Good luck
Tip: Before going with any development strategy, it will be very helpful in the long run if you thoroughly research it first, so you dont have to change later. For instance, you make an entire chat system with php, then you learn what node.js is, and you wish you were dead.
