Michael,
I'm thinking your plastic might have been the reason for your mold problems. I just leave the pots exposed to the elements. The only time I shelter them is after they have started to germinate.
It is probably easiest to wait until February or March and plant the seeds THEN. That way they aren't exposed to the elements as long and they germinate quite well with most dangers of freezing over, at least here in the Pacific NW. You may want to do it later if you have later frosts.
Regardless you will have such fun with your seedlings! I think everyone should dso this at least once for the experience.
Kevin
