doc g 's advice is pretty good.
what I would do is buy 1 and only 1 cloud gh cost you about .0038 btc or under 1.80 usd at current prices. leave it sit for a week and study what it does. you need to learn the ins and outs of cex.io to have any chance of success. and you need to be able to buy low and sell high to make money in the cex.io side of the company. you can not make money buying hashes and mining. other then btc goes from 480 usd to 4000 usd. Since you already have the money in btc do not convert it to hashes.
Do you have a place to sell btc for usd. coinbase is the standard company for that. do you have your very own btc address? both cex/ghash and coinbase addresses do not belong to you.
I used the company below to make a wallet
https://blockchain.info/wallet