Hey I've downloaded a couple of maps and each time i go to play them they wont work. Just brings me back to the original waw menu.

Try using T4M

Download:http://ugx-mods.com/forum/index.php?topic=8092.0

how are you trying to start the game?

If it's taking you back to what looks like the main screen it's one of two things
1 you installed it wrong, but if you used an installer that isn't the problem
2 you are downloading maps that have to be launched with the console command (generally they don't have a custom main menu so when you launch the mod it looks no different) press the ~ then type map themapname
Most maps that require that state it in the description where you downloaded it