I'll fish with a minnow on one of these and set both hooks through the back of the minnow so it floats level just off bottom. They're actually relatively easy to make and I'll put one on a MH Rod with a 25-30 lb line and set it up in an iFish Pro.
As for spacing, I usually make them so there is no more than 6 inches total in line (3 on each side for each hook)