Federal Bills: You can get information on the status of a Federal bill by calling Congress (202-225-1772). For information on Presidential action call the White House Clerk (202-456-2226). Or you can look up the bill bill status on Thomas.
Thomas can also give you a list of all the bill that have reached a particular state in the legislative process. So if you need a list of all bills that have passed the House, passed the Senate, been cleared for or Presented to the President, etc., can go to Thomas and click on "Bill Summary & Status" for either the current or previous Congresses (back to the 93rd Congress(1973-74)). Scroll down to the search for "Stage in Legislative Process," choose the appropriate action and click the button.
To track the status of Federal bills, you can set up a free alert on Congress.gov or Govtrack. You can also use a subscription service like CQ Roll Call, Lexis or Bloomberg Law. On Lexis you would set up an Alert in the LEGIS;BILLS database.
For an educated guess on whether a pending bill will pass, search the Billcast database on Lexis (LEGIS;BLCAST) or Westlaw (BC).
State Bills: For information on state bill status and state-level bill tracking, see the State Bills and Bill Tracking entry and the entries for individual states.