Annie, I use a deep litter (wood shavings mostly) in my coop and have had similar questions. For now, I clean and start the floor litter twice a year and so have been trying to time the removal to suit my gardening seasons. In the early spring, I clean out the coop and create a (or add to an existing) compost pile which I turn periodically until I use it later in the year for cool weather garden bed prep. In early autumn, I do the same with the intent of using this material for the next springs bed prep. Throughout the year, I add whatever leafy/woody plant material and food scraps that aren't suitable for the chickens, and I aerate/moisten it periodically. This experiment has worked quite well for the garden; getting the timing/quantities of adding material in the coop has been trickier for me.
