You should download the bitaddress.org website and then transfer it to another computer, which will never go online again. There are people claiming that generated addresses are stored somewhere on the computer, and if you go online these addresses can be retrieved.

The printer is also a problem, because most printers have some sort of storage for the printer buffer, and this can also be retrieved. The bigger printers and photocopiers even have a harddrive. If you are very paranoid, buy a old second hand computer and printer and use that to create offline wallets. Never go onto the internet with these devices again.