It depends on the complexity of the contract. Here's a nice breakdown of cost associated with contract deployment:
https://hackernoon.com/costs-of-a-real-world-ethereum-contract-2033511b3214 For a simple contract, it would cost a few cents but more complex ones can cost a few hundred $$.
You can create smart contracts and deploy them on http://remix.ethereum.org/. Alternatively, you can check out this cool platform for a more visually appealing understanding of how contracts work:http://eth.build/