I've been working on my lichen identification skills. Below is a brief, pictorial tour of the process.
It's been a fun (and frustrating) learning process. If you're interested in learning more about lichens and how to identify them I recommend "Lichens of the North Woods" by Joe Walewski. I was recently given a copy (thanks Heidi!), and while it's may not be comprehensive, it's very manageable, and easy to use with a lot of information and great pictures.