How many sheets should a 3-hole punch handle for everyday office use?

For typical home, school or office use, a 10–12 sheet capacity model is enough and far easier to operate one-handed. If you regularly punch full reports, training manuals or classroom packets, step up to a 40-sheet 'reduced effort' model so you're not fighting the lever. Anything above 50 sheets is really aimed at print shops and church/admin offices.