Speaking in terms of sprinting as an adjuct to your weightlifting routine, not in terms of sprint training, a good way to organize your program is to think of total time spent sprinting. So, if I were to do a session where I do a 30 sec sprint, rest, then a 20 sec, rest, and a 10 sec, rest, and repeat for another round, that's a total of 2 minutes spent sprinting. I could have also just done 12 sprints at 10 seconds a sprint. You can use that total, divide it up however you want (personally I keep mine at around 30 seconds or shorter), and work to increase that over time. So the first two or 3 weeks might be spent on just developing a base of conditioning, so you just use 2 working minutes, and then when you've adapted to this you increase your total work time to 3 minutes, etc. For rest, that's again up to you and depending on your goals, but don't sell yourself short on it.