Parity Ethereum supports state-orientated programming of Smart Contracts with the Solidity programming language for the Ethereum blockchain. The wallet contains an integrated Solidity development environment allowing you to write, compile, and deploy contracts.
The native Ethereum token is called Ether (ETH). In addition to Ether, additional assets and Tokens can be handled by the Ethereum blockchain. The Parity Ethereum wallet supports any ERC20-compliant token by displaying balances and enabling transfers to be as simple as Ether transactions. Read more on Token Deployment and the Parity Token Registry.
There is a 10-part Tutorial on how to write dapps. It makes significant use of React and Bond-based UI technologies together with the Parity counterparts. By the end of it, you'll have some familiarity with all aspects of dapp-authoring including contract deployment, transaction posting, state-inspection and event-tracking. Examples of common operations and useful functionality when building a dApp using oo7-Bonds can be found here. See also Deploying Dapps to Parity Wallet, Dapp Discovery and the Parity Dapp Registry.
By default, when simply running parity, Parity Ethereum will connect to the official public Ethereum network. In order to run a chain different to the official public Ethereum one, Parity has to be ran with the --chain option or with a config file specifying chain = "path" under [parity]. There are a few named presets that can be selected from or a custom JSON spec file can be supplied.
Parity supports private chain and private network configuration via Chain specification files provided with --chain. In addition to the usual [Proof of Work Chains](Proof of Work Chains), Parity also includes [Proof of Authority Chains](Proof of Authority Chains) which do not require mining. More details on the available options can be found on the Pluggable Consensus page. See also the Demo PoA Tutorial.
Last but not least, have a look at the JSONRPC Guide.