If you do some web searches on "kambucha" you should find a lot of information about it, so I won't duplicate what you can already find. I'll just list my recipe and state my two cents.
In a clean pot, I boil about 3.5 quarts of water. Then I turn off the heat and add 1 cup of sugar, about 3 tablespoons of green tea (usually gunpowder), and 3 tablespoons of black tea (often Lipton tea bags). I wait for this to cool until it is warm, but not hot to the touch.
Next, I strain this mixture into a very wide mouthed tinted jar that can hold at least a gallon. I picked it up at Ikea. The main thing is just to have a large, wide mouthed jar. I add in about a cup of already made kambucha tea to increase the acidity. Finally, I add in the kambucha "mushroom" and cover with a cotton cloth.
How long you ferment the mixture depends on the temperature. For me, this means that the tea cooks faster in the summer. It will usually be ready in about 6-10 days, although I sometimes leave it longer for a sharp, vinegar tasting batch.
I've tried making it with ginger tea. This works but I don't like it as much.
I will supply a starter mushroom to anyone willing to pick it up. I currently live in downtown Chicago.
Is Kambucha a panacea? Does it live up to all of the hype you will find on the web about it? No, of course not. I think most of its benefits are similar to those of drinking a small amount of apple cider vinegar in the morning. So, I take a few ounces in the morning mixed with water and believe I derive mildly improved digestive benefits. I'm not ruling out additional benefits, but I haven't seen any convincing evidence of them.