I’ve been a fan of Eyewitness Books (Enciclopedia Visual Altea en españoll) for many years now. They are not just fun educational tools but also an excellent reference for my Illustration work. Here is the thing: when you think about vikings you picture, well… you standard viking warrior. But when you browse one of this books you get a glimpse at many other objects and elements that shaped their culture, even little things you wouldn’t imagine like the arm of a wooden viking chair carved with little cat’s heads or a deer’s antler carved with a love message.
The structure of the books is pretty dynamic, pages full of images with explanatory texts surrounding them. They have a few special editions that include transparent sheets with cross sections of temples, houses, ships, etc.
I can easily jump to internet whenever I need to do research but -if the topic permits it- going back to this little treasure is way more fun.