yeas and nays - A senator who wants a roll call vote on a pending question asks for the "yeas and nays" on the question. The request will be granted if seconded by one-fifth of a quorum, but this action does not bring debate to an end; it only means that whenever debate does end, a roll call vote will occur.
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 THOMAS Web site. Information from the present back to the 93rd Congress (1973) is available on THOMAS.
For information on the Senate, Congress, the legislative process and the federal government, the Virtual Reference Desk is a good place to begin.