Loading multi-player maps

[Lurker-]

hey, i have been trying to figure out how to host a server with more than the default maps that came with the game. i wanna use the maps i've downloaded in the process of joining other servers, maps such as deck 16, quake 3, bedrooms, etc etc. but every time i try to host a server, the maps section only shows the default maps. so how do i use the downloaded maps? what folder do i put them in to make them appear on the map list when i try to run a server. thx