I got a lot out of
Carnoy, Castells, Cohen and Cardoso (1996) *The New Global Economy in the
Information Age*. Penn. State
and this introductory classic (in case it doesn't rate as a classic over
Hettne, Bjorn (ed) (1995). *International Political Economy: understanding
global disorder*. Ferwood, Halifax, Canada.
I first took an interest due to Stuart Holland's (1987) *The Global Economy:
from meso to macroeconomics*. Weidenfield & Nicolson, London.
But then I ain't trained in this stuff, so have a look before you buy ...