Thank you for asking! There is considerable debate on this/these topics. I actually add new shavings about once a month, an inch or two. At least once weekly I toss the shavings or better, put scratch or treats in there and let the chickens toss it for me.
I also add shredded paper from time...
Lots of folks put down rolled vinyl to protect the plywood floor...that is what I have in mine, and it makes it easy to scrub and hose out when cleaning time comes around. I put pine shavings on top of this for the chickens bedding.
think about a poop tray under the roosts for daily cleaning...