The nice folks at UC Davis have a series of publications for you:
http://www.ipm.ucdavis.edu/PMG/PESTN...html#SELECTING
http://www.ipm.ucdavis.edu/TOOLS/TURF/

You've missed the best time for planting cool season grasses from seed, but
if you want warm season grasses, early next spring will be your target to
plant. Decide whether or not you're going to irrigate permanently.

If you need some quick cover for the soil for the winter, consider some of the
annual cover crops like buckwheat.

Kay