To install maps you must first download Winzip 7.0 or SR-1, once you have done that and set it up, choose a map to download, you have to download it to your outlaws folder which is c:\progaramfiles\Lucasarts\Outlaws by default  then what i do, is right click on the map and choose "extract" then a screen comes up that already has the folder to unzip it to and you just press okay, thats it!  your ready to play.