If you don’t have a clue about what is Ethereum or a smart contract, you should first read what is Ethereum.
The fastest way to get started with Ethereum smart contract programing is Ethereum Wallet. It’s a native application available for Windows, MacOSX and Linux. You can download it from the Github project.
Before anything, Ethereum Wallet needs to connect to the block chain and synchronize.
Once the sync is done choose the test network. On the test network any transaction will be done with test Ethereum so it does not cost you anything to develop. Keep in mind that while you are on the test network your contracts won’t be accessible from the normal Ethereum network.
Then you have to choose a password and don’t forget it. You don’t have to worry too much as the password will only affect the test network.
Once this is done you should see the Ethereum Wallet main screen displaying your account address and current balance which should be 0.
On the test network you can easily get Ethereum by selecting in the menu Start mining.
Let the app run a little and you’ll see Ethereum in your account. It can takes around an hour to get your Ethereum. In the future, you will need a small amount of Ethereum to deploy your smart contracts to the blockchain and interact with them. You can now start writing your first smart contract.