This video from Congress.gov explains how a bill is introduced in the legislature and the steps it goes through on its way to becoming a law. (Transcript available here.) The bill is introduced (either in the House or the Senate), and referred to relevant committees for discussion.
The vast majority of bills introduced during a session do not make it to the end of the process; they may be voted down, or Congress simply runs out of time. Even bills that die in committee are useful in public policy research, particularly if there are associated committee reports, debates, and hearings.
From National Latin@ Network.
Behind every law is a policy, and researching legislative history is a good way to determine what the policy is, and how Congress went about enshrining it in law. Elements of legislative history include bills, summaries, debates, and hearings. See the Law and Legal Studies LibGuide for more information.
Once you identify a policy area, bill, or law that interests you, the next step is to look at the legislative history.