Sort-of depends on what kind of fish your friends want you to smoke. Smoking usually is better for more oily fish.
When I do salmon I usually do a dry cure and smoke at about 225* until fish is about 140* internal. This is a hot smoke and is called kippered. Sometimes I wet cure also just for variety. You can also cold smoke some fish (maybe all?) at much lower temps.
Maybe try the Google search feature here and sure you'll come up with a lot of input.