Choosing the Right Scope for Your .22 LR Rifle - A Beginner's Guide

Question
Paul,  I want to buy a scope for a .22 LR rifle for shooting game around the farm out to 100 yards.  I've know nothing about scopes.  What power range do I want?  Are there types that clamp on if the rifle isn't drilled or tapped or grooved or whatever in order to mount a scope?  Are the $40 K-mart scopes worth buying?  Thanks, John

Answer
3x9 is enough but .22 LR maximuim effect range is 50 yards
and 75 yards .22 Mag. Past that the bullet drops rapidly
and wind will shift it as it decellerates.
Heavy barrel bench rest rifles can hit at 100 yards but off hand with hunting is beyond its range limit.

If most modern rimfire rifles are grooved for a scope.
Older ones may not be.
What type of rifle is it?

I would avoid cheap scopes and would recommend these.

http://www.bushnell.com/products/riflescopes/22rimfire.html