I attended a lecture on prarie planting a few years ago
Here is what I remember;
Results are best in early fall.
roundup or burn the area intended for prarie development, burn is better (not in Colorado though!)
Use prarie mix designed for the soil/hydrology class of the site.
Plant large areas with a slit seeder or seed drill.
Small areas till and overseed with a spreader, drag or rake area for good seed-soil contact. Then roll, using truck tires is perfectly acceptable.
water in if feasable
Maintainance for the next 3 years is to mow to 6 inches 3 times a year. This will help control undesirable plants, the tsall ones will be topped and the short ones will be shaded out.
fall treatment is to mow sort or preferably burn. Burning is a natural part of the prarie ecology and will supress woody invasives.
annual burns are concidered regular maintenance for prairey sites