Alex Ramon is a proud bike geek who used to work in a bike shop. He doesn't anymore, but he has decided to share his knowledge of how to do various kinds of things with bikes (maintenance, repairs, modifications, etc) on BicycleTutor. There are currently 48 video tutorials on the site, and chances are there's a video in the archive that answers some of your bike questions.
From the About page: "The purpose of this site is to help people learn how to fix their own bikes. While I don't work in a shop anymore, I still have all of my tools and some parts so I might as well share what I know (and learn from you). I'm on the lookout for different kinds of bikes so I can cover as many different jobs as possible. I'm keeping a tidy list of all your requests and I imagine we'll have 1-200 videos on this site over the next two years."If you know other good sites with bike how-to/tutorials, please let us know in the comments below. Thanks!
You can also 'like' BicycleTutor on Facebook.