"Organized by policy area, each chapter contains summaries of legislative activity, including bills passed, defeated, or postponed."
Encyclopedia of the American Legislative System
Browse for other books about Congress:
House of Representatives website
Legislative Branch Resources on GPO Access
The Center on Congress at Indiana University
The Dirksen Congressional Center
OpenCongress -- "a free, open-source, not-for-profit, and non-partisan web resource with a mission to make Congress more transparent and to encourage civic engagement"
Thomas (Library of Congress)