I recommend Coursera's [Economics of Money and Banking](https://www.coursera.org/course/money), a Barnard College, Columbia University course.

When modeling I recommend considering [Hyman Minsky's words](http://digitalcommons.bard.edu/cgi/viewcontent.cgi?filename=1&article=1068&context=hm_archive&type=additional): 

> The alternative to beginning theorizing about economies by positing utilty functions over the reals and production functions with something labeled K (called capital) is to begin with balance sheets of various agents.

Thus a bottom-up model of interlocking balance sheets is better than simplistic math equations.