If the Mac version gives an Unidentified Developer Error follow this link:
http://www.imore.com/how-open-apps-unidentified-developer-os-x-mountain-lion
Install your wallet. Wait for it to sync for about 10-30 minutes on core desktop versions.
Create a Receive address: With your wallet open, go to the receive page. Click on request payment to create a deposit address. Copy this address.
It is recommended that you encrypt your wallet and add a password. Restart your wallet. Record your password in a safe place, you cannot get this reset.
Backup your wallet: If you don’t backup your wallet and your computer has a problem you could lose your Dash. Always backup your wallet BEFORE you send Dash to it.
For desktop wallets: Select File / Backup Wallet. Store your wallet file in a safe place.
For mobile wallets: Select backup and email wallet or backup to a microsd card. Store in a safe place.