Colleen, as Phoebe indicates, you can make composting as simple or as complex as you want. Some people make such a science out of it you wonder when they have time to do any gardening. :lol:
Essentially, there are two major forms of composting: hot piles and cold piles.
The advantage to a hot pile is that in addition to decomposing the organic matter the heat is hot enough to destroy perrenial weed seeds and many (but not all) plant pathogens. The downside is that it's a lot of work. The pile has to be turned every three to five days. It's one thing to to that when the pile is only a few forksfull of stuff; quite another when it's several cubic yards.
A cold pile is, basically, the way God makes compost. You just toss the stuff in as it accumulates, and let it sit until it decomposes. This is a slow process (mine sits for a year after the last additions), and does not generate enough heat to kill either weed seeds or pathogens. The up side is that it's low maintainance, requiring no work until you screen the finished compost.
There is a third category generically called "sheet composting," in which you spread the layers of organic greens & browns directly in the garden. They initially serve as a mulch. And you can either turn the stuff in at the end of the year or just leave it sit and the worms will do it for you. Here, again, there is no heat generated to kill off baddies. Nowadays this method is mostly known as lasagna gardening or as the Ruth Stout method. Ruth did not, contrary to popular belief, invent it. But she promoted it heavily.
My big bin was built out of pressure-treated 2 x 4s. Basically it's a three-sided corral, divided in the middle. This gives me the two compartments I eluded to earlier. After a dozen years it's finally starting to fall apart, and I'll have to rebuild it this fall.
FWIW, a few years back I did a major story for Mother Earth News on compost tumblers. My conclusion: With the possible exception of the Compos-Twin, none of them is big enough to produce enough black gold for vegetable gardeners. And, given their costs, they only make sense if you live in an area with restrictive covenents against open compost piles.
If you should choose to look at them, ignore the manufacturer's claims as to speed. They do not work any faster than a well-maintained open pile.
One other thing that perhaps need clarification. From a composting point of view there is no reason not to include animal proteins in the pile. The reason we ignore them is because they attract nuisance animals, such as rats, raccoons, and the neighbors' dogs and cats.
They have taken the oath of the brother in blood, in leavened bread and salt. Rudyard Kipling