Auditing in SharePoint Server 2007

How do I enable auditing?
There are several options:
For a whole site collection: In 'Site Settings' click on 'Site Collection Audit Settings' or navigate to http://xxxx/_layouts/auditsettings.aspx Select the actions you want to audit.
For a particular document library: In 'Document Library Settings' : 'Information management policy settings' Click to create a local policy and select Auditing and actions
For a particular content type: Just create a content type and click on 'Information management policy settings'Click to create a local policy and select Auditing and actions
To view the Audit Log Reports you have to activate the Reporting feature:
Navigate to:
http://xxxx/_layouts/ManageFeatures.aspx?scope=SiteFind Reporting and click on 'Activate' (if not activated)Go to 'Site Settings' then you should see 'Audit log reports'.You can click on the link and then you can select the report you would like to generate.
The reports that you can generate are as follows:
Content activity reports
Content modifications
Content type and list modifications
Content viewing
Custom reports
Run a custom report
Information management policy reports
Expiration and disposition
Policy modifications
Security and site settings reports
Audit settings
Security settings