After de-thatching and aerating your lawn it may have thin or bare spots that would benefit from overseeding. The first step is to remove the debris brought up by thatching and rake the soil to break up the crust on the surface. This will encourage better contact between seed and soil. Next, sow the seed at a rate of 4-5 lbs. per 1000 sq.ft. and press it down gently. Keep the area moist until the new seedlings appear.
See also Aerations & Overseeding