Bills are proposed legislation from the House or Senate. Bills from each chamber are assigned a number in the order in which they are introduced. Congressional sessions last for two years, and when a new session begins, bill numbering for that session's legislation starts over.
Examples:
H.R. 8 (the 8th bill from the House of Representatives during a session of Congress)
S. 535 (the 535th bill from the Senate during a session of Congress)
The text of bills can be found in a number of resources including those recommended and listed below. Bills are also often found within specific Congressional Reports and also in the Congressional Record. Since bill text can change significantly over the course of the legislative process between introduction and enactment, be sure than any version of the bill that you find is the version you wish to see.
Westlaw provides the following:
Congressional Bills includes summaries and the text of congressional bills and resolutions introduced into the current session of Congress.
Historical Federal Bills, 1995 -
Bill Tracking includes summaries and status information for current legislation. A legislative calendar is also included.
CRS Bill Summaries for introduced bills, are written by the Congressional Research Service, for the current session of Congress.
Lexis provides the following:
Bill Text (Congressional Full Text Bills) 1989 - present (in separate databases by congressional session)
Congressional Bill Tracking Reports 1989 - present (in separate databases by congressional session)
Congress.gov provides:
Text of Congressional Bills, 1989 (101st Congress) - present
ProQuest Congressional provides:
Bill Text 1789 - present