Resting too long between sets can reduce the effectiveness of your power development workout. It’s also an easy way to annoy people waiting their turn on the equipment. If you’re not sure how to plan this element of your weight training, a study published in the Journal of Strength and Conditioning Research offers some guidelines to consider.
 

The peak power output of 18 men and 20 women was used to group subjects by strength. Then all subjects did 5 sets of bench throws for 8 reps using 40% of their 1 rep max. 

Factoring in reported rates of perceived exertion, ability to maintain power output and muscle soreness 48 hours after training, stronger subjects only needed 2 minutes of between sets rest while weaker subjects required 3 minutes.