Yes, but begs the question, why?
If you do low weights and lots of reps (particularly concentrating on lowering them slowly) it build up connective tissue rather than muscle so can help rehab from or prevent injuries.
You should aim to do a similar umber of reps regardless, i.e. if your doing low weights and lots of reps, you do fewer sets, if your doing low reps you have to do more sets to compensate.
However many you do if you dont eat protein the muscle wont build up so stick to a normal diet if you don't want the body builder look. But don't cut it out either as excercise is destroying the muscle fibres so that they'll rebuild stronger/more of them. If you went on a reduced protein diet doing resistance excercise will actualy result in muscle loss!
for good guides either ask a trainer at the gym or the mens health site has a workout generaator, tell it how long youve got, what your aims are, and if its relevent what part of the body your working on that day and it picks a set of excericises.