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
View audit log reports
Following link will help you to understand the following points:
· Events available for audit log reports
· Available audit log reports
· View audit log reports
Please let me know in case of any queries/questions so that we can discuss and sort it out quickly.