There is a way for layers to vote for maps. Players can type
'listmaps' to see the maps available to vote on, and then they type
'votemap X' where X is the coresponding number of the map.
Only after a certain number of players have voted for the map
which one player has started a vote on, will the sever change map.
Press ~ (the button to the left of 1) to bring down console.