SharePoint 2013: How to enable the audit log
To enable the audit log by using Central Administration:
- On the Central Administration home page, in the Application Management section, click Manage service applications.
- Select the Secure Store service application.
- On the ribbon, click Properties.
- From the Enable Audit section, click to select the Audit log enabled box.
- To change the number of days that entries will be purged from the audit log file, specify a number in days in the Days until Purge field.
- The default value is 30 days.
- Click OK.
Configure audit settings for a site collection
Please use the following link in which Microsoft has given a very detailed description that references each and every minor point regarding audit settings:
It consists of:
- Auditing event information
- Trimming the audit logs (new enhancements in SP2010 and SP2013 as compare to earlier versions)
- Configure audit log trimming
- Configure events to audit
MS Reference
View audit log reports
The following link will help you understand the following points:
- Events available for audit log reports
- Available audit log reports
- View audit log reports
MS Reference
http://office.microsoft.com/en-us/sharepoint-help/view-audit-log-reports-HA102772739.aspx