When can I let them...

I just let mine out and they go back to the coop to lay. When they are done, they come back out and join the group. But with new layers, I wouldn't let them free range until they know for certain where they are supposed to lay.

 

I just let mine out in the morning before i go to school and at night the come in to roost so i shut the door. And they should come in to lay all mine do except when the first start laying they will lay any where i would take a easter egg or golf ball and put it in their nest so they no where to lay.

 

I also put some fake eggs in their nest. Every once in a while I catch one of my hens sitting on a faky.
I let mine range in the morning but if one feels an egg "coming on" it will stay in the nest. Be carefull, I stepped on my very fist-long awaited egg because they hadn't figured out what the nests were for yet.