Just get some hay, wheat straw, leaves, grass clippings or whatever natural material that you can find that will decompose. Table scraps--no meat--old fruit, egg shells, any of this stuff. Put in in a pile or in a bucket or barrel, I have a 6 ft square area with fence edging, dump it all together and put the chicken poop on in. Mix it up and add more material, mix it up again and add more poop, mix it up and add some leaves grass clippings or straw. Don't forget to add any vegetable table scraps you have. O and add some more poop along with the bedding material you use in your coop!
It won't take long and you will have some of the best compost ever made. If you made your pile on the ground it will soon begin growing great big fat juicy earthworms -if you don't see any buy some fishing worms and add them- they will help all the material decompose. Shovel it all to one side -volume will decrease as it decomposes- and add new material to the empty side. In a couple or three weeks mix it all together and add some more material and poop. Mix and add, mix and add, mix and add!
Next spring fill your wheelbarrow with the decomposed material and haul it to the garden, spread it heavy before mixing it in the soil. You just put some of the best fertilizer God ever created on your garden and your vegetables will grow better than ever before.
PS--don't leave all this chicken poop in the garbage bags, use it now for compost, there is no reason to save it as chickens are always pooping. If you leave it in the bags it will decompose in the bag and generate a lot of heat that could have potential side effects especially if stored indoors--did I hear someone say fire hazard?