How fascinating to see that both Ian B and Ian C on this forum are both mandolin players.The great thing about the instrument for a beginner (and I will *always* be a beginner on it!) is that the tuning lends itself to helping you make an impressive sound fairly quickly... noodling away on some improvisations using only open, second, fourth and fifth frets, on any couple of strings (but preferably the middle two pairs) will help you build up speed and will actually sound rather good. Great for the self-confidence.
Mandolin is the kind of instrument on which, to people who don't play it, something fairly simple can sound quite brilliant.
God luck! - Ian B