If you are handling personal data then the BCS has put together the Personal Data Guardianship Code[1]. It lays out the responsibilities of organizations and people have when handling personal data. It is also a handbook for people who provide their information to services (e.g., online and forms etc).
At first glance it provides a better understanding of how to go through the processes associated with the data life span, as it is called. Its simple and clean layout and formatting shows that the target group is quite large and everyone should read it.
The Code also provides example where appropriate and help the reader understand a section slightly better.
As mentioned quite often by the BCS, on the site and in the document, the Code is not a legal document but a guideline and the users should refer to the relative legislation, e.g. Data Protection Act etc.

Links used:
[1] BCS, Personal Data Guardianship Code - http://www.bcs.org/server.php?show=nav.10666