In my office, in plain sight (so lawyers can see it) I have a graduated wire folder holder. I really can't think of any other way to descirbe it. It has multicolored file folders each with the name of a case I am handling in big huge lettering. Inside the folder is everything my supervising attorney would need to know about the case, should I get hit by a bus, hit the lottery or get a marriage proposal from Johnny Depp.
I've been using this system for years and its very helpful for both the paralegal and the attorney. Your type of case would determine the information that you keep in your folders. Some suggestions would be lists of opposing counsel, court phone numbers, schedules, special rules. These folders have come in handy lots of times because the information you use the most is always right at hand.