printers need drivers to print
on ios there are no real printer drivers you can install so you can
1. get a printer which support the generic interface called airprint apple will not update it so printers which don't support the airprint std will work it's up to the printer to support the interface
2. get an app from app store which let you print to your printer my samsung wifi printer don't support airprint but using the samsung printing app I can print to it just fine
3. take a look at Netgear Genie it's an app which is suppose to make non airprint printers work it don't require ones wifi router is made by Netgear
made it work on osx but not win7 because there it require acrobat to be installed
it works when your computer is on and the netgear genie app is running