I assign them to beds but they wont sleep...the beds are spread out and the workers are the ones following preston....

any advice?

Can they get to the beds? NPC's have trouble with low fences and high steps.

Also when in edit mode are the beds actually assigned? Point to them and see if the vault boy icon is red (not assigned) or green (assigned).

NPC's assigned as Guards do not sleep, but like having an assigned bed.

Sturgis can be assigned to a Scavenging Station, and will use an assigned bed.

June Long will always use Her assigned Bed after Farming, but She has to be able to get to Her Bed.

Mama Murphy can be assigned as an early guard, but I prefer to place Her "Special Chair" under a Disco Ball and surrounded by Cat Pictures beside Her assigned Bed.

Preston is protected from Us assigning Him a Bed inside a Foundation Fortress

I use one building for the Longs, one for Mama Murphy, and Preston/Sturgis share. I have placed the Longs and Mama Murphy in the same House and all three will use Their Beds.