You can identify the type of grass you have and find lots of other lawn-growing info here: http://www.scotts.com

Oklahoma info: http://www.tulsamastergardeners.org/blackbox/trf_ok.htm

Very good Oklahoma info:
http://www.tulsamastergardeners.org/cgi-bin/redir.cgi?fsnum=6420

The best times to water are early morning or early evening, when there is generally less wind and heat. Cool, calm conditions limit evaporation, allow greater soil penetration, and reduce runoff.

Most watering systems apply water faster than the lawn can soak it in. Pause your watering when puddles or runoff occur, and let water penetrate the soil before resuming. Water soaks in at different speeds in different soil types. If you have extremely sandy soil, it could take as little as half an hour for an inch of water to soak in. With clay, it could take 10 times longer — about five hours — for an inch of water to soak in.

Keep a newly seeded lawn moist, but not soaked, during the germination process. Too much water can cause a poor germination process. A light mulch over the seed will help keep the soil moist. As the new lawn grows, reduce the frequency of watering and increase the amount. After four to six weeks, treat the new lawn as an established one.

For a newly sodded lawn, soak completely for about two weeks after placement, watering every day or two. This will allow the root system to become firmly established.”