I have to disagree with the folks that say not to bury the grass seed and that it needs light to germinate. For maximum germination the seed should be covered with 1/4" to 3/4" with soil. An overseeder is the very best way to achieve this but is quite cost prohibitive. I would suggest spreading the seed over soil that has been well loosened then rolled. The area should then be raked lightly with a york rake (should have guage wheels) at a very shallow depth to cover the seed. It takes practice. You will move seed around, but this is for larger areas, not spot treatment, so if you do it right, it will have even coverage. By burying the seed like this you accomplish the foolowing:
1: It will be much easier to keep the seed moist and not be dried out by the day sun. A huge benefit in large areas that are not easily irrigated.
2: The seed will not suffer as much from exposure to to rain erosion, wind erosion, and birds eating the seed.
3: The rate of survival will be much higher as the grass will have deeper and stroger rooting when it does become exposed to the sun, wind, and rain.
Like I said, an overseeder is best. No other method will provide a higher rate of germination or suvival. Any good landscaper that installs quality lawns will tell you the same thing. In the absence of an overseeder, then use the method I described, or you may also install a light layer of staw. The problem with the straw is that it is easily displaced by wind, and if not installed carefully, it can suffocate and rot areas of grass after it germinates if too thick.