Several Avery labels are 33 per sheet, 1x2-13/16 inches. The different numbers represent different pack sizes, colors, materials, adhesives or printer compatibility (copiers, inkjet or laser), but they all share the same template.
You can design these using the 5351 template in Avery Design & Print Online.
You can also use a template built into Microsoft Word or download an Avery 5351 template for Word, Photoshop, Illustrator, InDesign or Pages.
Here's some information on recommended printer settings.
If you want more information about a specific Avery label, search for the product number on avery.com.