3. Go to 'Billing' and input your info. (You can use your Empty Prepaid/Debit Card/VCC)
4. Scroll below and enter the promo code 2014SSD for 10$ credit.
5. Create a new droplet (server) with your free cash (you can create two 5$ droplets or one 10$). They have pretty good configurations, especially since you got them for free. Pirate
6. Follow this tutorial to start mining BitCoins : http://goo.gl/K5mB8P
Basically what you just did is rented a cloud server for free (it's usually paid) and set it to mine BTC. A friend of mine in another forum says he earned 28$ with it already (since yesterday). Good luck!