A couple of external resources

plus one that stackoverflow is a great resource. the only caution is that when you first sign up and post a question
its almost a certainty that someone will downvote your question and call you a noob in the comments
for example today someone posted a question and the first comment was "hire a developer"

however don't let this detour you from posting! on the flip side stackoverflow is a great place to help other people. i've learned a lot just trying to answer questions.  

its also very inspiring to see how worldwide codeigniter is.