For your salmon it's best to salt the fish in advance, just rub salt on and leave it for an hour or two, this helps the fish to take on the smoke. Meths in the burners, scattering of chips inside the base. This is a bit of trial and error and how much you put in will determine the strength of the smoke flavour. I find normally a very thin layer is enough. Wash off the salt and dry then put in the coker, light your burners and off you go. Depending on the thickness, size of the fish about 15-20 mins should do it.
You'll soon get the hang of it Gill.