Britannica Educational Publishing 
Legislative Branch of the Federal Government [PDF ebook] 

The Legislative Branch, created by Article I of the Constitution, is comprised of the House of Representatives and the Senate, which together form the United States Congress. This book not only studies the powers of the legislative branch and the organization of both houses of Congress, but also examines the legislative process and how a bill ultimately can become a law. This book gives readers a detailed look at how their government really works to both create and pass lasting legislation.