I'm not sure which post you are talking about, if you can put a link I can see where the images are at and put them back up.
On my boat, the front deck was already there, so I just glued straight to the aluminum. For the center deck, I got a piece of plywood, treated it with some water seal type stuff (2 coats), then glued the carpet to that. The glue I used was a spray on glue from 3M.
If I could do it again, I'd put some kind of padding under the carpet just to make it more comfy.
There's a good article about bass boat recarpeting at: http://www.bassresource.com/fishing/bass_boat_carpet.html