How do you know if a lawyer is good?

I've got good news and bad news for you. The good news is that the majority of lawyers are competent (or better), meaning that for most cases, you are likely to be able to find someone who is going to be able to represent your interests at least reasonably well. The bad news is that distinguishing between a C+ lawyer and an A+ lawyer is very hard, and takes a lot of effort. Unfortunately, I don't think that the profession as a whole does a good job at helping clients make informed decisions.