If you have never smoked fish before, this link may give you one cook's view of how to go about it, along with a variety of brine recipes:
http://bbq.about.com/cs/fish/a/aa030400a.htmWith what little smoking I have done over the years, I favored the sweeter apple wood over the slightly bitter hickory.
Are you fishing for carp or suckers? Both are excellent smoked, but I prefer suckers pickled. I let the experts in my neighborhood do both for me - an older man does the smoke house thing, and a friend of mines' mother does the pickling. Their brine recipes are know to no one else but them.
Jonathan