I would really have to say that it depends on what muscle groups you are referring to. Legs for instance can withsatnd alot more work and therfore can have more sets per excerise than that of say arms. BUT as a general rule, I do 5 sets per excersie. First with lighter weights repping out really high reps then increasing each set with more and more weight as I go reducing the nnumber of reps as well.
Tobey