To begin with, you need to download and install Votifier here: http://dev.bukkit.org/bukkit-plugins/votifier/

Running the server once to generate the configuration and keys. You need to then choose a port in the Votifier configuration and make sure that this is open to the public.

Votifier needs listeners installed, so that it knows what to do when it receives a vote notification.

Once the plugin is fully configured, go to the Votifier configuration page in your server administration panel. Open up the public key, found in Votifier/rsa/public.key, and copy the contents to the corresponding field. You will also need to fill out the server name and port, to match your server details. Usually the server will be the same as the address you advertise and the port will be whatever you configured it to be in your Votifier configuration.

Once you're set up, a username box should appear on your vote page. Entering your name and submitting a vote will send a notification to your server and Votifier will act on it based on the listeners you installed.

Thanks for reading!