Bitcoin is a digital currency, created and held electronically. No one controls it. Bitcoins are not printed, like dollars or euros. They can be produced by anyone across the world in a process called ‘mining’, in which computers use software in order to attempt to solve a mathematical problem.

You can buy Bitcoins at any of the following sites:
Bitstamp.net
Bitfinex.com
btc-e.com
Poloniex.com
Coinbase.com

Make sure you follow:
Bitfinex Code Tutorial
Twitter Bitfinex Updates
Bitcoin Referral Code