What is the ideal time to rest between sets? I've heard anywhere from 30 seconds to 2 minutes. Does the amount of reps per set affect the resting time?
usually with heavy weight and low reps your recovery can be anywhere from 2 min to 5 min if your doing high rep low weight stuff you normally only rest for 20 secs to 1 min. Try to listen to your body and work out when you are ready but don't be lazy
A personal trainer I worked with had me doing 45 second rests in between sets. This was a change from my norm - he had me doing a "hypertrophy" phase, as opposed to my usual strength routines. It made the sets much harder despite the lesser weights, and I believe I got good results from it in "bodybuilding" terms anyway.
Shorter rests is much harder due to lack of rest :P but it geared more towards: hypertrophy, stamina and recovery.
Longer rest is mainly used for stuff that is technically difficult and heavy and low volume stuff where your 'form' is more important: absolute strength (1RM stuff)
It will affect you depending on what you want to 'achieve' with your routine.
JRockwell you have yourself a decent trainer from what I hear.
Generally speaking, there should be an inverse correlation between sets and rest invervals due to nervous system factors; fewer reps usually means greater loading is used employing more CNS activation, whereas more reps = lighter weight and less CNS activation. The rationale is nerve cells take longer to recover than muscles do ...so in short, fewer reps = longer rest, and vice versa.