I booked myself a device (http://www.aliexpress.com/snapshot/6207479202.html) for extraction, in the realities of the pool as it is important.
Please don't buy this, it is obsolete.
At the current difficulty you will need couple TH/s not GH/s to obtain at least ROI if you plan to start a mining operation.
And you will need : couple thousands of USD, a reasonable power grid, and a proper space where to place your miners because they generate plenty of heath and noise.
If you want to experience how the mining really is, but you don't have all above, go an buy some cloud mining contracts. You will see how hard the mining for Bitcoins it is.
The best solution is to buy Bitcoin directly from a trusted exchange an trade these coins for a higher price later.