The iPad and iPhone are not Mac computers. They use a different operating system.
If you want to print from the iPhone and iPad, your options are:
1) Buy a new AirPrint enabled printer and have it connect to the network using wireless....not USB
2) Try an App like Printopia on your MacBook Air to see if it will work with your current printer.
I suggested Printopia because I have used it, it works well, and there is a free trial. There may be other Apps that do this, but I have not tried them, so cannot comment on them.