I am also getting into the BTC market for the first time. A single 330 mh/z block would not yield enough income based on the current difficulty and cost to run it. (There are calculators out there such as this.
http://www.bitcoinx.com/profit/ )
From the research I've gathered, you'll need to start with a minimum of 10gh/z and a good pool to sit in. But this is all theory since I have no hardware currently. (This is just my personal opinion and I am far from a pro BTC miner). It also seems that this was a bad time to start seeing as ASIC device prices have skyrocketed (In good reason, BTC went up so does the equipment designed to mine them!)
You can look into cloud hashing solutions if you don't want to have the hardware overhead. (I am looking into both options). Hope this helps guide you some what!