truth is, there's no one-stop shopping for tattoo machine information. there's so much heresay in the industry and bad information that people adhere to like religion that you're going to have study a lot of different, sometimes conflicting information and experiment a lot to find out what works.
That being said, joey D's book has some good information in it. The Godoy book is good but may present some problems to a novice IMO. The TAM articles by Seth Ciferri have some good stuff in them. Machinegun machine articles have lots of information but a lot of it is strictly experimental (Truspring anyone?). Hanging out in forums like this, figuring out who knows their stuff, and listening to them is probably the most direct route. Finding a good builder and 'contributing' to the cause may work but it could get expensive and they still may not be willing to hepl you very much. And personal experimentation, trying different things until you find out what works best for you. The problem I've noticed with the personal experimentation is that a lot of people give up before they get everything right and end up working with inferior-running machines and incomplete information.
It's one thing to do something because someone says to and another to understand why you should do it, I would encourage everyone to focus on the latter on of these. If this doesn't help, email me.