The easiest way to print from an iPad is to use a printer that is compatible to AirPrint. AirPrint is the printing protocol used by the iPad. If your printer supports AirPrint you can print directly from the iPad to the printer via your Wi-Fi network.
Look at this page from Apple support. You will find a list of all Cannon printers that support AirPrint. If your printer is listed you should be able to connect.
If your printer is not listed then the ability to print becomes more complicated.
If your current printer is a USB printer, then perhaps the easiest way is to activate/install AirPrint on your Mac or PC.
Activate AirPrint on a Mac;
Install AirPrint on a PC;
Otherwise, there are also a number of printing apps available in the iTunes App Store that will help you print to a USB printer connected to your computer. A popular one is Print Central. Look for the ones that come most highly rated.