The New York Public Library has a large collection of these cards viewable from their Digital Gallery.
Churchman's Cigarettes produced a "How to Make a Map" series for boy scouts. Here are some of their cards with the text that appears on the back.
"Scouts should first practice observation, and notice all the landmarks (such as hills, churches, trees, rocks, gates and bridges), so that, if necessary, they may draw an accurate map of the surrounding country. The four points of the compass should always be put in, and it is a very great convenience when a map can be, as nearly as possible, drawn to scale."
"It is a difficult matter for a scout to accurately draw a map of water, This, however needs only a little practice and a perfect knowledge of the different signs agreed upon to represent the different boats. The specimen given at the recto is a very good one, showing a very complete map of a village in the vicinity of water. The letters P. T. signify that the village possesses both post and telegraph office."
Gallagher, LTD also issued a "How to Make a Map" card. Here is the front and back of the card.
Map Reading Class was also a card subject.
Some cards depicted airline routes. Here is the route from England to South Africa.