Freesteam.org/Gmod/
Gmodfiles.com
Fpsbanana.com/games/73
when you have downloaded an add on, extract the file to: :C/Program Files/steam/steamapps/<your user name>/garrysmod/garrysmod/addons. you put in maps to : :C/Program Files/steam/steamapps/<your user name>/garrysmod/garrysmod/maps.
Put addons in this folder: C:\Program Files\Steam\steamapps\<steam name>\garrysmod\garrysmod\addons
All steam games update themselves automatically.
You can buy it at the Steam Store. Check the related link.
Install steam (steampowered.com) and you can buy it on there. $10 and you get automatic updates through steam and servers.
on addons ( steam/steamapps/garrysmod/garrysmod/addons)
Go to garrysmod.org and download various addons. These after download are usually extracted to the [Steam Install Folder]/steamapps/[Steam User Name]/garrysmod/garrysmod/addons folder. But these addons have installation instructions most of the time.
Go onto garrysmod.org and search for samus, assuming you know how to install addons.
It depends on what you want to download, first get what you want to download off of garrysmod.org Maps go in the steam/steamapps/(username)/garrysmod/garrysmod/maps file addons go in the steam/steamapps/(username)/garrysmod/garrysmod/addons file
Depends on what kind of things you want on your game for addons, and Maps get them off of GarrysMod.org Heres how you install them Program Files > Steam > SteamApps > YourUserName > GarrysMod > GarrysMod > Addons Program Files > Steam > SteamApps > YourUserName > GarrysMod > GarrysMod > Maps
well its just like addons really but if you are using garrys mod 10 theres a mp3 player addon and you can add your own music and sounds but theres a soundthing calledEasy Use BILLY MAYS EXOSOUNDSsearch that on garrysmod.org and download it then transfer the easy use billy..... folder with all the files in it to [if you use the steam version] program files/steam/steamapps/your user name/garrysmod/garrysmod/addons. just look for the folder addons in garrys mod folder if you torrented or not using steam- program files/valve/garrysmod/garrysmod/addons.check youtube too
Steam
when you have downloaded an add on, extract the file to: :C/Program Files/steam/steamapps/<your user name>/garrysmod/garrysmod/addons. you put in maps to : :C/Program Files/steam/steamapps/<your user name>/garrysmod/garrysmod/maps.
There is, 10$ Steam
10$ through Steam
Put addons in this folder: C:\Program Files\Steam\steamapps\<steam name>\garrysmod\garrysmod\addons
Buy Garry's mod 10 off of steam.