I suggest you use the Search feature at the top of the page to look up Deep Litter Method. You will find multiple posts with lots of ideas and suggestions on keeping your coop clean.
I use the DLM mentioned above and will be cleaning it for the first time next month. The chickens moved in last June so it won't have been quite a year since I started with the pine shavings. I've just added to them all winter and have no smell at all inside the coop. It is very important that it stays dry though from outside weather or from their waterer leaking.
The deep litter method https://www.backyardchickens.com/web/viewblog.php?id=1560-DLM
I will also add that my coop has linoleum flooring, so the litter doens't seem to break down to well...so ever though I deep litter, I need to dig quite a bit out every several weeks I think the some reason are it tends to be pretty humid over the winter (with the amount of snow we have had) and I could also add some more ventilation. (which will happen before next winter!)