I often buy coins at Kraken in order to buy IOTA at Bitfinex. Which coin is the best?
Read A Primer on IOTA by Dominik Schiener and check the beginner introduction to IOTA at r/Iota.
If you are interested in buying Iota, you need a trading account at a cryptocurrency exchange. We use Kraken and Bitfinex. If you sign up for Bitfinex via this link, you can save 10% on your trading fees for the first month.