What are you trying to accomplish?

The best thing I have ever been introduced to is Periodization training. You pick out some standard compound lifts (bench, incline, squats, BB curls, etc). You do 4 or 6 week phases. It breaks out like this:

Phase 1- 15 reps on every exercise for 4 weeks
Phase 2- 8 reps on every exercise for 4 weeks
Phase 3- 12 reps on every exercise for 4 weeks
Phase 4- 6 reps on every exercise for 4 weeks

Here is how it works, it is a combination of weekly goals and intensity. For example, lets say your incline press for 8 reps is 225 and you hit 225 this week. Next week you go up to 230. If you hit 230 for 8 reps, you go up to 235 the next week, if you miss it, you try again the next week. Most weeks I was able to go up every week. Bigger lifts, like squats, deads, go up 10 lbs a week. For biceps you might only go up 5 lbs a week. One of the things the guy that taught me this program that always stuck with me is this, if my plan includes 3 sets per exercise and I am able to hit my reps on all three sets, I have failed to do the first set with enough intensity. This is the Dorian Yates approach. Dorian always said if you could do the same number of reps two sets in a row, you failed to use enough intensity on the first set. The second and or third sets are really just to push the muscle further, you are not expected to hit the rep goal on those sets.

I did this for about 18 months straight after I first learned about it and it was one of the best growth phases I ever had. I also found out exactly what my body parts responded best to. For example, I found that my chest responds very well to 8 reps, my triceps respond better to 12 reps, my biceps respond better to 6 reps, my calves respond best to 15 reps, etc. I also had my best jumps in strength I had ever had as well. I reached goals I never thought would be possible.

I would suggest to anyone looking for answers on reps and sets to give this a go for a good year, then you'll have a very good idea how your body responds to sets and reps. Also, make sure you stick with those base exercises. If you mix up the exercises this program won't work, so use compound exercises and two hand exercises for arms. BB curls over DB curls, stuff like that.