In this day and age it is difficult to keep track of all the passwords, account numbers and contacts that are spinning around a Company. Take the time to develop and store this in a central location. It makes finding information and dealing with administrative things much simpler.
You should include anything you can think of from an administrative perspective into this. Account numbers. Websites that you use (and passwords). Service providers. Contact details. etc.
You can also look at storing things in a central location online. Services such as WEBEX are absolutely brilliant and also give the added benefit of ensuring information is secured and accessible from anywhere in the world.