Start with http://predictionbook.com/predictions/future
Predictions you aren't familiar with can be as useful as ones you are: you calibrate yourself under extreme uncertainty,and sometimes you can 'play the player' and make better predictions that way (works even with personal predictions by other people).
r/Fitness does a weekly "Moronic Monday", a judgment-free thread where people can ask questions that they would ordinarily feel embarrassed for not knowing the answer to. I thought this seemed like a useful thing to have here - after all, the concepts discussed on LessWrong are probably at least a little harder to grasp than those of weightlifting. Plus, I have a few stupid questions of my own, so it doesn't seem unreasonable that other people might as well.