^ Listen to some earlier concerti. Beethoven is a great one, though IMO the 1st and 2nd are rather bland. The C minor concerto is an excellent one (that I'm messing around with at the moment), as is the 4th. The 5th, known as the Emperor concerto, is a little harder to follow, but still nice.
Mozart concerti are also good choices; No. 20 in D minor, No. 21 in C major, No. 24 in C minor, and No. 27 in A major probably being the best of the lot.
Mendelssohn also has one in G minor that's fairly digestible.