Check out the Bicycle Tutor website for a ton of videos showing you how to do all sorts of repairs and maintenance to your bike. Bicycle Tutor is run by Alex Ramon.
Here's a little bit of information about Alex:
"My name is Alex Ramon. I’ve been a bicycle geek since early childhood, spending my twenties working as a mechanic in some great bike shops. My cycling passions include flatland bmx, unicycles and cycle-touring and I have a lot of fun mountain biking and road riding. I’ll basically ride anything with pedals. 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)."
There are currently 40 videos on the site including: How to fix a flat tire, How to adjust your seat height and angle, How to tune up your bike and Basic bike repair tools.
Check out the Bicycle Tutor videos, blog or forum, for a ton of cycling repair and maintenance information and advice.
Lynn Smythe AKA the Bike Diva