Try getting an adult piano method book from your local music store. My final semester in high school, longer ago than I'd like to admit, I invented an independent study class in piano. I picked up a book for ten or fifteen bucks, and by the end of the semester I knew my way around the keys pretty well. My technique is horrible, but I never wanted to perform on piano/keyboard anyway. I just wanted to know how to play. I'd recommend you just drop a few dollars and go the book route. You'll know your chords in no time.