Is it easier to teach yourself how to play the keyboard or guitar?
The guitar is easier to get good at quickly, however piano takes quite a while before it actually sounds half decent. I’d go with guitar first, but the option is entirely up to you. If you want to learn piano/keyboard some books that may help you are Piano Adventures by Nancy and Randall Faber. For guitar searching Google to learn basic chords always works, I find Chordie is a good source for chords to songs if you want to find that out. Here are some links: http://www.pianoteaching.com/ http://www.chordie.
