Client side downloading

I seem to have a problem where the files for textures, props, whatever, do not get to the client side of my server, so, if I go online on my computer, and download say, the RPG-7 swep, i can see it on my gmod server (Hosted online and works fine) but, if someone else who has not downloaded it straight to their computer tries to use it, its a giant error, but still useable, can someone help me out and explain to me how I get the servers files onto the clients computer? The same with adv dupes