Walter Beeler's collection of 15 trumpet solos.
No, I don't think I'll master this book any time soon, but it is still fun to play around with. There are a few pieces in there that I would consider playing for special occasions at my church or a wedding and there are some that I wouldn't attempt at this stage of the game (Handel flute Sonata, Schubert Allegro,etc).
Guess I better stick to jazz!
Greg