After you have enabled forum voting, you can start adding votes using the "Vote Manager" section located in your Forum Module -> Post Voting tab.
From here you will manage your votes. You can add a new vote by clicking the "Add Vote" option to the right of the screen.
From the Add/Edit vote window you can create a custom vote name, upload a custom icon or choose a pre-made icon from our huge galleries by clicking the green "Select from Vote Library" button.
After you have chosen your name and image, you will need to assign the vote a votes value between -500 and +500. This will be the number of forum votes (Not website points) the voting option gives a user when they receive on the forums.
You can also set some permissions here and restrict which user groups can use the vote and which forum sections the vote is applied on.
Once you have your vote set up how you want, just click "Save Changes" and you should see your vote option start appearing in the Vote Manager main section.