what should be the rest time between sets?

[spesmilitis]

and should that also apply between exersises?

 

[Warboss Alex]

Rest as long between sets as you need to give 100% again. No set time..

Same with exercises really. Finish up one exercise, put away your weights, log your results in your notebook, have a drink of water/gatorade/whatever, set up whatever you need for the next exercise and start warming up for it.. when you feel ready to give 100%, start your first workset.