Depends if you're wanting a revolver or simply a 'handgun'.

The Thompson break-open handguns make the catridge selection forever wide but since I assume you're new to hanguns I think the before mentioned 30-30 is a good one.

For revolvers I'd look into the Single Action Rugers (Blackhawks) The new 'hunter blackhawks' come with rings and scope mounts built in...I love mine. I'd stay with .44 mag because the .357 just isn't going to cut it out past 100yards and the they aren't available in 454 casull. The Double Actions (Redhawks) are...but its recoil is not for the beginner.

In .44 magnum pick something 240gr or above and practice, practice, practice. One thing my Blackhawk has taught me is that being accurate with a rifle doesn't mean jack when you first transfer over to handguns.