We always learn from books and nowadays from internet. But IT is such a field, where we learn a lot from our colleagues. They are our best references, but there are software developers, who either feel shy in asking their doubts or are not thankful to others, so ultimately when they ask next time, they get zero answer.
IT is vast and nobody can have complete knowledge on any subject. Everyday, we come across different problems. So Ask...Don't feel shy if you don't know X.
I'm not suggesting you to bother someone unreasonably and asking for spoon feeding to learn anything. NO, be polite, thankful, directly come to the point, understand and support others.
If you want to sustain in the market, then you would have to keep yourself updated with latest IT tools, and technologies. Following are the few sources: