There’s a piano teaching method called Instant Piano for Hopelessly Busy People, which is being offered by the Cambridge Center for Adult Education. I’ve been listening to the introductory music lesson podcast by the series creator, Robert Laughlin to get an idea of what I might expect. I like how he describes all the chords in terms of how they sound, and what’s important and what’s not. Also helpful are the various “music theory” resources at 8notes.com.