I attended a free bicycle repair class last night. It was teh awesome. I learned so much. My suggestion is shop around. There are some mom and pop shops out there who will teach you all you need to know about your bike. And they are not in it to make a buck, but do it for the love of the bike.
Besides, I found out there were so many things wrong with my bike, seeing as how the guy I bought it from put it together wrong (tire was on backwards, breaks were mal-adjusted, etc.). There are so many things that I can list why I will not return to the shop where i bought my Raliegh from, but let's just say the guy charged me $10 to "fix" my seat post on my old junker bike. I found out after at the Bike Instead of Work Event I attended that I was ripped off. Chris from Hollywood Pro Bicycles, who was giving free bike tune ups at the event showed me how to adjust my own bike seat. It was so freaking easy I was embarrassed. Yeah, you live, you learn.
My instructor last night did a complete overhaul, taught me a lot and didn't charge me a dime. I am loyal to that bikeshop now. If you're in the area, visit Boulevard Cycles in Sherman Oaks and see Craig, he's an older man, tell him Paula sent you, the chick with the Red Raleigh who's tire was on backwards.
It was also a great way to take my mind of a break up that happened earlier in the day.