Buffs are a great choice for your first birds,I started with them too. Just to clarify nest boxes are for laying not sleeping. Your girls should sleep on a roost which is an elevated pole of some sort that should be higher than the nest boxes so they will sleep there and not the nest boxes. Chickens poop all night long which is not a good thing for where they lay. If you start with chicks block the nest boxes off so they can't get in their till their till their about 18 weeks old. When you do open them put in some kind of fake egg in there so they get the idea of where to lay, I use golf balls and they have worked well for Me.