Start with this:
http://www.crisisprevention.com/Resources/Knowledge-Base/Physical-Restraint-Training
Having been on both the administering side and the receiving side, I can say this: it was pretty easy for properly trained people (who cared about doing things properly) to restrain me. I’m not small (6’1", 210lbs), and there was nothing I could do about it.
This is also very likely similar to what @anotherone’s wife uses (though exact systems differ, as do the venues they are used in…).
