A catcher spends most of his/her time crouching or squatting. Doing squats, at least 3 sets of 10 reps daily, will put you in great condition for the position.
Squats are very good, as this is the position you'll be sitting in most of the time! Essentially, any leg workout (leg press, leg extension, hamstring curls, etc. ), and improve your upper body strength and arm strength.
