For document availability by date and by source, see this chart.
Committee reports summarize the action that a committee took on a bill, and committee reports are often thought of as the most useful documents for identifying legislative intent. Unfortunately, reports are not issued for every bill.
A special committee called a conference committee is composed of members of the House and Senate and is used to reconcile the difference between bills passed in each chamber. A conference committee is used only for some bills. Conference reports are published as House reports.