I'm somewhat of a novice myself at trolling but I've been doing for a year now. What everyone else said is good advice. I have two on my 16 ft. aluminum. Hand cranks with no boom. I put one on each side and they work great. I attached them to some plywood and clamp them to the boat so I can remove them when I need to. Cabela's sells an inexpensive one (can't remember the brand name but I know its not Cannon)for about $50 and it comes with a 4lb. ball and clip. Its a good way to try it without putting too much money in it.
The only advice I can give you is to use a long, flexible rod, like an ugly stick. When a fish hits and the line comes free, a soft rod will pick up the slack better than a graphite rod.