Be sure to go through the whole thread. The mentioned tutorials are all really good, but you'll want to focus mainly on the training schools. I personally opted to go with Geeks To Go, but they're all good choices. Just get a feel for each forum and see which one you like best. And trust me...based on my personal experience...if you want to get into this, you definitely want to join one of those schools. You wouldn't believe all of the different things you learn that you most likely won't learn simply by following tutorials. I've gotten to the point where I can skim through a log and easily spot various infections, but I've still got a long way to go, and you always want to be meticulous (even if you're 100% sure that you know what you're doing).
Bear in mind...doing this is a long process. It isn't all that time-consuming (I only spend maybe three/four hours a week...not including time spent waiting on my instructors), but overall, it takes a decent amount of time to complete. It's very refreshing, though, and I'm grateful to oddjob for suggesting that I take this course of action. There's definitely a sense of accomplishment once I've cleared a log.
Anyway...enough of my rambling. Read through that thread and take the training into consideration.