Using the dashboard can be a simply way to check-in visitors.
How to check-in a new Visitor:
Go to the online Dashboard
Click on green 'Check-In' box in the top row
Select 'Visitor'
Enter Visitor details and click 'Create new Visitor'
The details should now show on your visitor log
How to check-out a Visitor
Go to the online Dashboard
Scroll down the Visitor log
Click the status and switch it to Check-out
The record should now be updated