I think this is great platform and I do get answers to what I post. I however am confused about how do I start contributing by answering some of the questions. I am wondering how people find out the questions that they think they can answer. Do you keep going through all the questions? Are there any filters which says I am basic/moderate/advanced user in some topics?
You can look for questions in areas you're good at. Click on a tag in the "Unanswered Tags" list in the right side of the screen in https://stackoverflow.com/unanswered/tagged/?page=5&tab=newest