That printer doesn’t natively support AirPrint, the feature introduced in iOS 4.2 that lets you print wirelessly to a small number of HP printers. If you want to print just photos from your iPad, try Canon’s free Easy-PhotoPrint app. We haven’t used the printer or the app, so we can’t vouch for them, but hey, the app’s free. Give it a shot.
If you want to use the printer for more than photos – to print documents, for example – try Netputing’s AirPrint Activator (donation requested; www.netputing.com/airprintactivator). Install it on a Mac running OS X 10.6.5 and iTunes 10.1 or later, reinstall your printer and enable sharing for that printer and you’ll be able to print from your iPad to your printer.
Ecamm Network’s US$10 Printopia (www.ecamm.com/mac/printopia) is another alternative that will also do the job. As Dan Frakes states in his review of this utility: “It doesn’t matter how a printer is connected to your Mac – if your Mac can print to it, your iOS device can print via Printopia.”