Vote lobbies are optional. Basicly, players are put in a lobby and eveyone get to vote for a map that they want to play. After the vote has finished, all players get sent to the map with the most votes.
/bw arena create <arena name> -mapvote Or click the paper in the Create an Arena section of the setuptool/bw arena setlobby <arena name>/bw arena setenabled <arena name>That's it!
Make sure that there're enough arenas to vote for.