The World Reference Maps and Forms  by Evan-Moor -  $19.95

This wonderful resource contains 92 maps of physical, political and blank continental outline maps of every region of the world. 

South America, for example, has a page of basic geographical facts, a map showing country outlines, a map showing mountains and rivers, a map with only the continental border (good for hsitoric marking), a blank map showing countries, a blank map of physical features (eg. mountans) for you to label yourself, then two maps looking at enlarged parts of the continent.  All areas are covered in this way.  You will find A4 sized maps for any purpose you could have. Suitable for any age.