Does anyone have any links, reference material or ideas for user logging/tracking. I am trying to get ideas on how to track users actions/changes. I am not so bothered about where they go, I want to track what they have done.

I have a system that users can enter (login) and alter information. Some of the information is open to, and can be edited by all. At present, I can trust all the users (partners) but I need to expand the system to users (employees) that I dont know and I want to track what each user alters and when.

I have been thinking of taking the username, datetime and query used to alter the information and recording it into a separate tracking table.

As this is a new area for me any ideas, links or references would be great.