+1

Square taper cranks generally need quite a bit, about 40ft lbs if I remember correctly. Unless you already have a trained arm for this sort of thing, there's no way to guess at it. You'll probably ruin your crank if you just tighten them down to whatever feels good. Ask me how I know.

I hardly ever use a torque wrench, but this is one that's too easy to screw up. Borrow one if you have to, at least to find out the proper torque.