I have been charged with setting up a database to track keys to employees and outside contractors. So far I have succeeded in setting up a nice relational database which allows me to connect a key to a client. Having a Client file, a Key specs file and a Main file. It has been getting me by so far, but it can definitely be improved.

I want to add in a history log. I want to be able to access a key and display all of the people it has been checked out to, with issue dates and return dates. Also I want to be able to access a client and see all keys that are checked out to them, and that have been checked out to them in the past.

Can anyone help me out with this?

You need to add a join file, ClientKey. Each record in ClientKey will contain the clientID, the keyID, the start date/time and end date/time. You could have a portal in the Client file showing keys lent to the client; you could have a portal in the Key file, showing clients lent to.