Yeah, sorry I wasn't trying to be snarky. It just annoys me when bike mechanics don't do things properly for their customers.
I do all my own wrenching for three reasons: First, I know things are done correctly, Second, I save quite a bit of time and money, Third I really have come to enjoy it.
I guess fourth would be the level of self reliance it gives me when out on long rides or tours... always a good thing.

My advice to you would be to begin reading the park tools site (it is excellent) and Sheldon Browns site (ditto). Instead of paying for the class, start investing in some tools. A simple multitool will allow you to do many things on most modern bikes, including adjusting brakes and derailleurs and tweaking bike fit. As you get more comfortable with simple mechanical stuff, work your way up to more advanced skills like replacing chains, working on older bikes with loose bearings etc. Buy good quality tools as you need them, and they will last for years. Also, if there is a bike co-op in your city, they will often have hands on classes run by people who want to teach others mechanical skills...

power to the people