I wouldn't water them until you're somewhat close to being past your last frost date, Jane. Wet and cold can cause seeds to rot instead of germinating. Or if they do germinate early then get slammed by frost you lose the seedlings too.
Once the nights are dependably above 40 or so, I'd say you should keep them moist. Or sow them somewhere more protected, like the south side of your house or garage, where they will stay warmer on cold nights, and then you could start misting them sooner to encourage germination.
I'm thinking back to when I had poppies that came back each year (self-sowed) when we lived in Utah, and yes, they were on the south side of the house under the overhang, where it was a great little warm micro-climate and things regularly bloomed a month earlier than the rest of the garden.
Oops, I forgot to ask what kind of poppies they are? - Shirley poppies are a lot cold-hardier than California poppies.
