I've played for seven years now, and keep learning. TTR's advice is right on target. Your first task will be to firmly plant a map of the instrument in you head, so that you know where to find the note you want. Most dulcimers are not chromatic. The "accidentals" you most likely have will be A#, C#, F#, G#. The major keys (plus their modes) you'll be able to play in will likely be A, C, D, F, & G. That covers probably 95% of all Celtic, mountain, old-time and bluegrass music. The vast majority of most music you'll likely encounter will be in D or G. You can also play in many other keys, but you'll just have to resolve the problem of missing accidentals. The easiest way is to just skip the note (but not the time value), but you can also play a complementary note (one that is in whatever chord is playing at that point). Each tune you learn will teach you something. Try to keep your playing area as compact as possible, and beware of crossing your wrists while crossing the treble bridge. If you have to cross your wrists, it usually means you started the tune on the wrong hand, or missed a note or a beat somewhere along the way. Most important, have fun, and think of playing as play.