For big muscles like the lats, quads and chest, 10-15 sets per muscle group. Bis, tris, hamstrings, delts, 6-10 sets per muscle group. Not including warmup sets, obviously (I would consider anything under 65-70% 1RM to be a warmup set in most cases, 1-3 warmup sets per muscle group). If you're a drug-assisted lifter, you can probably handle more volume, but if you're natural, that's probably going to be a pretty good amount of volume.