Classic of science (and mathematical) fiction--charmingly illustrated by the author--describes the adventures of A. Square.
The Forward - Isaac Asimov
The best introduction one can find into the manner of perceiving dimensions.
About the Author, Edwin A. Abbott
The author of more than fifty books on classics, theology, history, and Shakespeare, Edwin Abbott Abbott (1838-1926) was headmaster of the City of London School and one of the leading educators of his time. Thomas Banchoff is Professor of Mathematics at Brown University and author of "Beyond the Third Dimension".