Not too hard to get started. Once you have SNMPD installed and working just run:
When that is complete you will have to modify the Apache config.
Add the follwing to "/etc/apache2/sites-available/default" between the VirtualHost tags:
Then restart Apache:
Use the url http://hostname/cacti and log in with the username admin and password admin. You will be asked to change the password and then you're in!