Nathan Hale's Hazardous Tales Kindle Graphic Novel $3 Each
Amazon Kindle has Nathan Hale's Hazardous Tales graphic novels for $2.99 each. The nine volumes in the series are all in the top ten of Amazon's children's history graphic novels. They are humorous and sometimes a bit dark (See Donner Dinner Party) but are historically accurate and can be entertaining for adults too. Each graphic novel is black white and one other color shade. Most of the books support panel view.
If you only get one this weekend, I recommend Treaties, Trenches, Mud, and Blood (A World War I Tale). It helped me understand how that war started and what it was about.