A good starting point for information on Chemotherapy can be found in
Wikipedia.
CHEMO targets cells that are under going active division - ie cancer cells. As I have mentioned before, the lining of the digestive tract and hair follicles are also cells that under go active division, hence the side effects of chemo. However, more specialized anti-cancer agents are being experimented with. There are now some drugs out that target cancer cells specifically.
Cyanide kills everything - dividing cells or not. If you don't beleive me, go drink some. No, don't.
Many of the substances used in accepted cancer treatment protocols are derived from - guess what? Naturally occuring substances in plants like yew, may apple, and periwinkle. Where was your FDA when these experiments were going on? Tisk, tisk! How dare modern medicine make use of substances found naturally in plants? Unfortunately for conspiracy theorists, modern medicine does this all the time - WHEN THE SUBSTANCE HAS BEEN PROVEN TO GIVE RESULTS.