Is there any information online on how to do this. I see there's a backup function but no restore. Noob.
Technically you can dump your private key and write it down somewhere. However all you really need to do is make sure to 1) encrypt your wallet and 2) make a copy of your wallet.dat file found in %AppData%/protoshares on Windows and ~/.protoshares on Linux.
The wallet.dat file is small and fits easily on usb sticks, SD cards, etc. Make a few copies of it and keep them in different physical locations (home, work, etc.).
It is also important to understand that you should refresh this backup of your wallet.dat file at least every 99 transactions. The reason for this is that the wallet starts out with a pool of 100 key pairs that are used for transactions that require new key pairs. When you have burned through your pool of keys the wallet-qt client will create an additional 100 keys in the pool. At this point you would need to refresh all your backups of your wallet.dat file so that the new transactions using these keys are backed up as well.
If you need to use your backup simply install the client somewhere and copy your wallet.dat back into the directory you backed it up from. Once the block chain catches up you'll see all your transactions.
You can keep your wallet.dat file off line all the time and only drop it into a client data directory when you want to do a transaction. It doesn't need to stay in sync with the network until you're ready to do a transaction. None of my wallet.dat files with balances stay on a computer for more than the few minutes it takes to do a transaction. Even the best hackers can't steal a file sitting on an SD card on a shelf
Think of the wallet.dat file sort of like a SIM card for a cell phone. It's the only thing that matters...the rest is just generic hardware/software.