I'm assuming you have nest boxes right?
Add pine shaving or straw (but most don't use this since I've heard it attracts mites). I used wooden eggs to encourage my girls to lay their eggs in the boxes, some use ceramic eggs, golf balls or other.
Don't expect the perfect egg the first couple of times. Usually they are misshapen, without a shell, extremely small or have soft shells. This is normal and will normally fix itself as the hen matures. Also as they are getting used to the whole thing there could be eggs found just about anywhere, coop floor, run floor, under the roost; this too should right itself as they get more used to the whole business.
Also if you see one go into the nesting area, leave her be, if she doesn't feel safe she will leave and lay the egg some where else.