Butylated hydroxytoluene (BHT), also known as dibutylhydroxytoluene, is a lipophilic organic compound, chemically a derivative of phenol, that is useful for its antioxidant properties. European and U.S. regulations allow small amounts to be used as a food additive.
Like others have said, it depends... If you're doing sets of 8-12 reps with moderate weights, rest 60-90 seconds. if you're doing high weight low rep (3-5 reps), then rest 2 minutes And if you're doing real heavy stuff like squats, deadlifts, I'd recommend at least 3 minutes.
A set is the amount of repetitions one lifts in weight training in one setting. For example, if you lift 150lbs. 10 times, that's one set. The repetition is how many times the weight was lifted. In the example, it would be ten times.