Newbie needs some help, damnit

i just got Garry’s mod yesterday, and i want to download some maps and other kewl stuff from this site. im sure people have asked this numerous times but where do i extract the stuff? also, how do i extract Left 4 Dead to Gmod?

Extract to your garrysmod/garrysmod folder. Addons is for addons, maps are for maps, gamemodes are for gamemodes.

To get the L4D spawn menu you have to get a mod for that.

C:/Program files/Steam/steamapps/Username/garrysmod/garrysmod/

Left 4 Dead stuff isn’t officially supported in garrysmod, but here’s some stuff…
Survivors
Special Infected
http://www.garrysmod.org/downloads/?a=view&id=60312

extract your stuff to your c/(other stuff that varies)/steam/steamapps/(username)/garrysmod/garrysmod

where u put player models

Those will most likely be in addon format (In which case you place it in garrysmod/garrysmod/addons), if not then merge the folders(models, materials, etc) by extracting the folders into the Garrysmod/garrysmod directory.