How do you research an old class action lawsuit?

Federal or state court? If you know the federal court the class action was in, you might be able to pull the docket (the case history) from the PACER service (see related link). Google is not a bad place to start either. If its a shareholder class action, you can try the Stanford website (see related link). If you are really stuck, leave me a message on my board. Good luck.