The last two articles I've written for the Ancestry.com blog have focused on using their German geographic finding aids.
The first one was an overview of using Meyers Orts and the 19th and 20th century topographical maps at Ancestry.com. Those who have never used Meyers Orts might want to give the article a look as it provides a few examples and suggests additional finding references to help the user when working with these materials.
The second one was a follow up focusing on a family who just could not seem to stay in one place and whose records in the United States gave a variety of places of birth. It also provides suggestions as well about navigating the German topographical maps at Ancestry.com