Another thing to do is after putting down the straw and watering it in good, walk over it some. This will help push the straw into the ground and keep it from blowing away. It probably also helps get good ground contact for the seed. I had heard that you couldn't over water it, but found out that you actually can. After the lawn is established, it is usually best to use more water less frequently. While the seed is germinating, the opposite seems to be true, from my experience. Don't lay down too much water all at once. If possible, give a lighter watering in the morning then another in the evening. My first lawn was a disaster. My most second lawn turned out much better, much faster, and with a lot less work.
Kevin