As crazy and esoteric it may seem, syncing your Apple AddressBook to Google really only works when your Mac is synchronized with an iPod or an iPhone. Just plugging such a device and syncing with iTunes triggers the sync to Google. You can also edit a file on your Mac instead to get the same result, as describe on Lifehacker.com:
Change the "Family ID." value to 10001 in ~/Library/Preferences/com.apple.iPod.plist

Thank you Gina Trappani and Josua Ferris!

A great little freeware app called PearLabelizer does an excellent job where the Address Book isn't quite good enough: Printing all kinds of labels for mailouts.

Eine nette kleine Ergänzung zum Apple Adressbuch, um anständig Etiketten drucken zu können: PearLabelizer.

Hint 1: Add predefined labels like Avery, Zweckform and Herma from the PearLabelizer website. Download and drag & drop the .plld files onto your PearLabelizer preferences window.

Hint 2: Format your font appearance from the keywords in the Address Book tab in the preferences by selecting Keyword e.g. [firstname] and choosing Format from the menu.