It's real easy to get started. You can grow your own scoby (symbiotic colony of bacteria and yeast, aka mushroom) from a cup of black tea and a commercially purchased bottle of kombucha, or order/obtain a scoby. I ordered mine from www.HappyHerbalist.com. Even starting with your own materials, the site has a ton of info on do's and don'ts and things to look out for (like not additives while brewing, otherwise it may throw off the brew).
p.s. I am in no way affiliated with said website, it's just what I used and have liked it.
"You can demonstrate the purpose and limits of human digestion with a simple experiment: eat a steak with some whole corn kernels, and see what comes out the other end. It won’t be the steak."