Congressional Sessions lists all Congresses and corresponding years  - from 1789, when the 1st Congress met, through the current Congress.

You can access legislative information, by bill number or key words, from the Congress.gov website.  Information from the present back to the 93rd Congress (1973) is available on Congress.gov.

For information on the Senate, Congress, the legislative process and the federal government, the Virtual Reference Desk is a good place to begin.