Time in between sets

just a few questions that have been ircking me over time

At the moment my workout routine consists of:

Monday: Chest, Triceps

Tuesday: Back Biceps

Thursday: Legs

Friday: Shoulders/Abs/Forearms

How many excersizes are recommended for each muscle group? And how many sets are recommended? Does it differ between muscle groups?

Also, how much time should I rest in between sets? I was thinking about 1 minute 30 seconds.. is that too long? short?

Thanks

Rest between sets depends on what type of training you are doing, if you are training for strength, then low reps and a rest time of 2-3 minutes between sets, for muscle growth training then rest 60-90 seconds,

To start off, training is normally 2 exercises per body part and then after the first couple of weeks, increases. For large muscle groups do 3-4 exercises, then two for biceps, 3 for triceps, 2 for leg biceps,

Training sets again is dependent on how experienced you are at training, normally for someone who is inexperienced then is usually approx 3 sets, advanced 4 sets, and bodybuilders approx 5 or more sets, but again it depends on your routine, some routines only do 1 set to failure ...

I do just about the same routine as you,when i do chest and tri's i do around 12 sets on my chest sometimes a couple more but dont usually do less than 12 (flat press, incline press, flyes, then either decline, dips, cable crossovers)
then after chest i hit tri's with between 6 and 9 sets, 2 or 3 exercises.

Back and bi's i do.. only 8 or 9 sets on my back then 6 sets, 2 exercises on my bi's sometimes 2 more sets if i throw in a 3rd exercise.

with legs i do, 4 sets on leg curls, (hamstrings) then 3 sets each on squats, leg press and calf raises, if you do leg extensions then 3 or 4 sets for that.

Shoulders i do an exercise for rear middle and front delts all 3 sets so thats 9 then i do shrugs aswel so around 12 sets. I'd imagine forearms only need a couple sets as they get targeted on biceps day aswel.

hope this helps you