Counter circuit help

Need a simple sensor, circuit, & display lay-out to count rotations of a shaft (or pulley). rpm's will be relatively low (about 0 to 500), but need to count total rotations over a period of time. Sensor could be attached to the shaft or pulley. Any suggestions for this newbie? :? Thanks.

This type of project has been covered many times, but the consensus has generally been to use a microcontroller to interface with your sensor (perhaps hall-effect or optical) and use the micro to count pulses and operate your display. With those low speeds, this would be very easy. I would use the counter or timer input of a micro to interrupt a main program that just does nothing other than update a display and keep a running total of "ticks" from the sensor.