The iPad was designed to be compatible with Apple's proprietary printing format known as AirPrint. Printers using this printing standard will be able to connect to iOS devices. Here are the steps involved in printing from an iPad to an AirPrint enabled printer:
Using the App that you want to print from, find the button that initiates printing. Although this will vary from App to App, it is typically the Share to icon or File > Print. The iPad will search for the AIrPrint enabled printer which must be on the same wireless network as the iPad. If an AirPrint printer is found, it will then proceed to ask how many copies you would like and other additional printing options may be available. Hit print to complete the process.
Note that unlike a computer, the ability to connect the iPad directly to a printer using a cable does not exist. Wireless printing is the only way to print from an iPad.
The printers that are AirPrint enabled tend to be consumer grade type and although this technology has been widely adopted, it is less commonly found in commercial printing applications such as the photocopier printers found in schools. Therefore, it is more challenging but not impossible to print in an educational setting. The following are some potential ways to print other than using an AirPrint enabled printer (ordered from low to high tech):
1. For documents, email them to yourself and print them from a computer
2. For photos, transfer them to a Mac using AirDrop and print from the computer.
3. Transfer documents or photos to a cloud drive such as iCloud, DropBox or Google Drive and print them from any computer.
4. Some printers have a dedicated email address that you can send files to. HP ePrint is one example.
5. Use a printing app provided by the manufacturer of the photocopier or printer such as Canon or Ricoh.
6. Use a printing app such as Printer Pro or Print Direct to find printers on your WiFi network.
7. Install a program on your Mac or Windows computer such as Printopia (Mac), handyPrint (Mac), or O'Print (Windows) which will act as an intermediary between the mobile device and the printer. Printing will only work so long as the computer is powered on (with the program running) and the mobile device is connected to the same network as the computer.
8. Some hardware devices will allow a printer to be discovered by mobile devices when connected to the wireless network.
9. Another piece of hardware that is compatible with AirPrint is Apple's Airport Express base station which when connected to the same network as the mobile device and directly wired to the printer with a cable, allows full printing functionality.
10. Finally, if Apple is not working for you consider Google. Google offers a printing service called Google Cloud Print which allows printing from Google services such as Google Drive. This works for Google Cloud Print enabled printers as well as traditional printers.
By the way, some of you may have considered this solution but let me assure you that it does not work.