If you wants to keep track of suspicious activity happening in your domain or any particular task then you can set alerts by going to manage alerts section under reports.
Transcript:
Hello everyone, Welcome to my tutorial on Google apps. In this tutorial i will let you know how you can manage alerts in Google apps, you can go to the Reports section. You see there is a option Manage Alerts. This option enables you to send mails to super-administrator or any other recipients when ever there are these security breaches or may be you can consider these events or action takes place in Google apps. Suppose a new user is added you want all super admins should be notified about it or there is a suspicious login activity then you would obliviously want super admins to be notified about it. So you can turn on whatever you like or whatever your organisation needs/suits to Google apps. Suppose i would like to enable suspicious log-in activity. You can turn on by choosing this option here by clicking on this option. When you click over here you can see the mail is to be deliver to super admin. You can either check dis or un-check this. You may have some other recipients. Generally companies have webmaster or you may have some custom group to which you want to sens a mail. I will set some address which i have here, a user and i want suspicious login activity to be deliver to this user. I will click on save and its saved. As you can see email recipient for suspicious login activity alert will be received by this user.
Descriptive Explanation:
As i think above video explained everything but still if you are confused then please follow the below provided steps (with screenshot):
you will redirected to a page where you will see Apps usage activity graph, user status in your organisation and many options for many types of reports.
Here in above photo you can see manage alerts section.Click on this option and you will be redirected to page listed with events.
IN this page you can see all critical events are listed. you can set the alerts for these events to super-admin, any particular user, any particular group as per the needs of organisation by clicking option (turning on alerts )present on right side of each event.
And alerts will go to all super -admin as default if you want to change/add the recipient for any particular alert then click on Super Administrator(s) below the Email recipient. one window will pop up ,there you can fill the ID (any user/ group) to which u want to get notified for that particular event.
The mentioned email recipients will get notified when that particular event will take place.
If you have any doubts, please ask in comment section. Thank You