The short piece by Keynes THE GREAT SLUMP OF 1930, that I included in Towards an Economic Tutorial, is about as good a two page introduction to macro as one could hope to get, especially if the reader does the simple exercises in arithmetic that Keynes recommends.  Some of the links, especially Irving Fisher's The Debt-Deflation Theory of Great Depressions, the two Minsky links, and the Tobin article would make a good "Related Reading" list.

"It is not necessary to have hope in order to persevere."