I agree wholeheartedly with Darin's advice on REI clubs and forums. I also have learned A LOT from them. Two other things that have helped me a lot are: 1) working with a mentor who specializes in the kind(s) of transactions that most interest you, and 2) continuing education. Believe it or not, I have roughly 10 mentors. Some specialize in foreclosures, others specialize in transaction engineering, others specialize in doing extremely creative commercial deals, etc. The point that Darin and I--who are both investors--are making is that investing is an activity that you shouldn't do in isolation.
Get out there and start networking with some other investors, and don't be afraid to ask questions. Also, for the sake of disclosure, I'll share that I used to be one of the most introverted persons I knew. I used to HATE talking to anyone, and I'm still not terribly excited about talking about anything outside of my comfort zone (ie the stuff that I KNOW that I know). So, you have no excuses. If an introvert like I am could learn to network, then so can you.