When you feed down, its just like drilling. Let the tap catch and let the threads feed it down. Before you bottom out, let up on the handle and then the pressure is off it will reverse.
If it clicks when you let off, you are not letting off fast enough.
the dial thing around the bottom is the torque setting. Set it to about the # screw you are using. If you are using a 2-56, set it to 2, for example.
If it stops before you are though, let it back out a little and come down on it again. I never try to make entry with a tap twice, so I try to never come all the way out till its all the way done. But if you do it will work.
that dial has a set screw in it (I think)
There is a set screw in the collet that will lock up the tap but I never set it. I like to let it float a little so that it can take the patch of least resistance.
I broke a tap in mine a few hundred holes ago, and kept of tapping with the broken tap, heck it was still half there.
These things are like magic, they are worth every single penny of the brand new price! If you have ever cussed a tap, you will love this!