idle to a power peak in the 4400-4600 rpm range. That's with a stock set up. If exhaust/intake/heads change, power band changes. A lot of guys running head/intake/exhaust and stock cam peak in the 5000-5200 range.
MANY inexperienced racers (especially if they're younger) rev the motor too high thinking they're going quicker. Ideally you want to keep the motor in between the torque peak and the power peak. You take your gear ratios, and your torque and power peaks (from dyno runs) and do a little math. In our t-5's, the first to second gear shift occurs a few hundred rpm past the power peak - that allows you to fall back to the torque peak in second. The 2nd to 3rd shift occurs right at the power peak; and the 3rd to 4th shift occurs right at the power peak.
Back in the day when road racing the old C4 corvettes, we'd shift them at 4400-4600 rpm - that produced the best lap times. They'd rev to 5000-5500 but they were just making noise....
The shift points in my car (power peak 4900, torque peak 3800) are 5400 rpm 1 to 2, 5100 rpm 2 to 3, and 4900 rpm 3 to 4.