As chscag said, and as Apple says, Pages can print addresses from Contacts. That's it. Not from Excel, not from Numbers. But there may be a way to get what you want. Create a new user (System Preferences/Users & Groups). Copy your spreadsheet to the Shared folder. (Open Finder, click on the Macintosh HD icon, then Users and finally Shared and put the file there.) Now log out of your account and into the new one you created. You can now use Finder to go to Shared and retrieve the spreadsheet. Export to a CSV file and then import it to Contacts in that new user (You may have to do some research on how to do that, but Contacts CAN import CSV files.) Now open Pages and do the mail merge as you want to print the labels. Once done, you can select all the contacts and delete them, or if you think you'll be reusing them, leave them there. If you have multiple lists, you can create a group for each list and print from the groups. Once done printing, log out of that user and log back into your account. Your Contacts list will NOT have the lists you imported to that other user.