When researching bills, committee hearings, and committee reports, you are performing legislative history research, essentially researching documents created at each stage of the legislative process as a bill is introduced and proceeds through steps of the formal legislative process.
Hearings are held by committees and sub-committees to obtain background information on pending legislation, and also for investigative purposes. Published hearings can include oral testimony, written statements of witnesses, exhibits, studies, article reprints, & texts of bills under consideration.
Committee reports can be especially useful sources of legislative history at the federal level, as they often include a bill's purpose and scope, a section-by section analysis, reasons for recommending full chamber approval, any views of dissenting committee members, as well as cost and budgeting information. Conference committee reports are a compromise of the House and Senate versions of a bill and indicate the understanding of both houses.
For federal bill tracking on Westlaw: Statutes & Court Rules → Tools & Resources → Bill Tracking ** Use Advanced Search
For federal bill tracking on Lexis Advance: Statutes & Legislation → Bill Tracking
No federal bill tracking tool on Bloomberg Law. For current list of bill actions, look up the bill and review the Congressional Activity listed in the summary.
Westlaw, Lexis Advance, and Bloomberg Law all contain selected historical bill and records of Congressional committee hearings and committee prints.