Tap a few lightly with a hammer. If they crack or shatter they should be dry enough. Be sure to store them in a paper container, though; plastic or glass storage may cause them to mold if there is any moisture left in the outer hull.
Not familiar with CA growing but I would think pumpkins should thrive anywhere with a long, hot summer.

i always have just left them on a paper plate and towel for 2 weeks. At that point the seeds will have a thin skin falling off of them. Remove it and put them in a envelope with rice until spring. I did this with 30 seeds last year and went 30 for 30 on germination.

Yeah, the easiest way to tell is that the outer "skin" will come loose. Wait a week or two after putting them on paper towels or newspaper, then rub one between your fingers. If a transparent plastic looking film comes off in a sheet, they should be good to go.