A .22 DA revolver would be my choice if I was starting out. Good ones are usually pricey, but I think it's the best platform for learning, and allows for plenty of trigger time. Guns to consider, in order of preference:
Used S&W K-22, M17, or M18 - $400 - 800, depending on condition
New S&W M617 - 10-shot stainless, 4", or 6" barrel - $600 - $700
New S&W M63 - 8-shot stainless J-frame, 3" barrel - $600 - $700
New Ruger SP-101 8-shot stainless, 4.2" barrel - $500 - $600
Cheaper alternatives to consider:
Used H&R Sportsman 999 - $250 - $500
New Rossi R98 Plinker - $300 - $400
New Taurus 94 - $300 - $400
...but that is only if you are married to the idea of a revolver. The 3 above do not have great triggers and the last 2 can have spotty quality control. I would consider the semi-auto Rugers and Browning in this price range as having much better quality and greater potential accuracy.
