I bought this magnetic whiteboard from Amazon, and stuck it on our refrigerator door. On it, I have been posting various family history ephemera along with short descriptions of who and/or what are represented. Here are some examples below (click on each image for larger view):
Photos of relatives, past and present
Yearbook pages and report cards
Newspaper articles, including obituaries
Birth, marriage, and death records
Immigration and naturalization papers
Family letters and postcards
Military photos and/or records
Maps of important locations in family history
Photos of gravestones
Photos of family history places, including houses, schools, farms, places of worship, places of employment, and important historical places like, perhaps, Ellis Island
Family recipes (but be prepared to make them!)
Surname origins and meanings
The family history whiteboard can be whatever you make it! You can focus on one family line at a time or mix it up! You can use important family history dates like birthdays and anniversaries to guide you on what to post when. I do recommend leaving each post up for at least a few days at a time, because I think the repetition of seeing it over and over really makes an imprint on our memories.
Another tip: Get a plastic folder pocket and put adhesive magnets on one side. Every month or two, rotate out the items you want to feature on the whiteboard, and keep them in this folder. I stick the folder on the side of the fridge, and pull it out when I want to change the whiteboard.