My family used to own a used auto parts shop for over 20 years. Sold it about a year ago. From what I know, almost 100% of the auto salvage places link into the same database. So if you come looking for a part, I can get it for you. If you call, come in x amount of days and I will have it, if its not already in the yard. Works pretty well, but shipping can get expensive.
As for new parts, the database also allows you to order those, it works out pretty well. There is also a very standard 30 day warranty on parts. I used to mess with people and tell them to up their warranty like the rest of the industry...
At any rate, I would learn some more stuff and then go for it. Definitely lots of room for improvement IMHO. The only thing is there are a crap ton of parts. And some of the compatibility can get confusing.