Hello, bit of a newb question here... if you're saving your currencies locally, do you have to:
1) have your wallet app running 24/7? (if not, how often should you run it?)
No, you do not have to have it running 24/7. How often you should run it depends on which wallet you choose (Bitcoin-Qt, Armory, Electrum, MultiBit,
https://blockchain.info/wallet), and how patient you are.
2) backup the .dat file more than once? (if so, when should you make another backup?)
It depends on which wallet you choose. If you use a deterministic wallet like Armory or Electrum, then you only need to back up once. If you use a wallet that generates new addresses using a random seed, like Bitcoin-Qt, then you will need multiple backups. In the case of Bitcoin-Qt, I'd say every 20 transactions would be a good "rule-of-thumb", unless you are generating a LOT of new addresses in the "Receive Coins" tab.
Is there anything else you should do to make sure your coins don't evaporate into the ether?
Choose a password that is very complex and nearly impossible to brute-force, then don't forget what it is.
