Oh, and don't forget the air button - it's essential to the instrument so make sure you learn to use it along with the bass buttons and don't leave it for later. One of the problems playing in D or G major is that in many tunes most of the notes are played on the push so you need to be able to get lots of air into the bellows quickly when you get the chance. The opposite is true for the Eminor tunes.

And remember - have fun with it!