Q: Can you print from an iPad?

Only with an AirPrint enabled printer.

AirPrint is a proprietary technology only available in certain printers (Note: not all wireless printers).

http://support.apple.com/kb/HT4356?viewlocale=en_US&locale=en_US

A few examples may be found on the Apple Online Store.

http://store.apple.com/us/browse/home/shop_ipad/ipad_accessories/printers

AirPrint

http://support.apple.com/kb/ht4356

To print directly from the iPad, yes.

There are indirect ways.

I notice that your profile mentions a MacBook Pro running Mountain Lion. If you can arrange to have it on any time you wish to print from your iPad, you can run software on your MBP to receive AirPrint jobs from your iPad and send them to the printer. The software I use is called Printopia, but there are others.

I was able to print to my HP Envy, but the size was always 5 x 7, and usually too small. I was unable to change the size, until I downloaded the HP ePrint app, which nicely interacts with the HP printer.