In a nutshell:

Start your compost pile with 25:1 brown to green organic matter.
You can add anything that was once alive but is now dead (although meat, bones, and human/dog/cat feces are not recommended).

Your compost pile should invite millions of microbes that, like all pets, need food, water, and exercise! 

Food: organic matter, green and brown.
Water: your pile should be wet enough to feel icky but not stick to your hands.
Exercise: turn/stir your pile once per week!

Your pile should be warm and steamy. It should not stick to your hands or be soaking in water!