I have a Small Pontoon Bass buster that I use.  It's made of a hard plastic and Stirofoam. I bought a Fish finder And I'm not sure where to place the transducer.  I bought an adapter and placed it at the bottom of the trolling motor but I dont get good readings. Would I be better off Gluing it on the bottom? Any advice? :-/

what type of depthfinder is it? I'd be concerned that it dosn't work right on the trolling motor because that is exactly how I was going to tell you to mount it

I've been mounting them on trolling motors for years and the only problem I've ever run into is with some of the variable speed motors is you get interference running in the slower speeds that will make the screen black while the motor's running. This is only on variable speeds, never had a problem with the 12/24 motors that have the numbered speed controls, other than sometimes they will make a spike when you start them. THere is some grounding and shielding you can do to help cure the problem on the variable speed motors but need to get with TM manufacture for that fix.

I have a Humminbird 535.  Its pretty good. Now, should I have it pointing stright down or should I have it at an angle? Sorry if this is stupid question...I've been fishing for about 9 months  but I spent half of it Bank fishing. Now that I got a little boat, I'm trying to learn all I can before I make my  big purchase.....

You want the transducer mounted so it will shot as straight down possible when the boat is resting in the water.