When planning group policy on a Windows 2000/2003 domain it can be quite confusing to remember which parts of the policy are being applied to each OU in the active directory.  Fortunately Microsoft have created plenty of a spreadsheets that you can use to capture the settings so that you know exactly which GPO is doing what.  You can then keep track of the GPO and re-create it if you accidentally delete it.

1.  For planning Policy on Windows XP download this simple spreadsheet.
http://www.microsoft.com/windowsxp/using/productdoc/gpss.mspx 

2.  Another more complex spreadsheet that lists all of the policy elements on separate sheets with registry keys can be downloaded from:  http://www.microsoft.com/downloads/details.aspx?familyid=ef3a35c0-19b9-4acc-b5be-9b7dab13108e&displaylang=en

You can download the templates that I have used successfully in the past.  I updated them so that the group policy would align to Window 2003 server policy templates.

Windows Group Policy Spreadsheets

I have seen somewhere a tool that will document existing group policies, if anyone can find it and post details of it and how to use it I am sure that would be useful.