Garry's Mod Problem

hello all sorry for my poor English.I wonder if you could help me with my problem that I can not put some addons because I do not see the models and sounds folders so I do not know where to put files and the game works.Thanks to all

[editline]2nd February 2011[/editline]

there is a way to raise the image of justine bieber?

for XP users : My Computer/C/program files/steam/steamapps/(YOUR USERNAME)/garrysmod/garrysmod/
If no sound folder make one. For 7 pretty much the same thing(for me at least.)