Bozilla,
I'm not an expert by any stretch of the imagination but I built a floating dock and think it came out pretty well. I attached a picture so you could see but more to brag a little bit. My pond finally hit full pool and I was able to attach the gangway to the dock. I built mine with plastic barrels and let the barrels dictate the spacing of the joists. I didn't use any plans but made it a 10x10 and figured out how to best get 14 barrels under it. I purchased my hardware from dockbuilders.com and was very pleased with their service. Even if you didn't buy hardware from them there are lots of pics on their site and am sure it would give you some good ideas. I used 3" green deck screws for the frame and 2 1/4" for the decking along with the galvanized hardware.
Good luck and make sure you post some pics of the completed project.
