MAINE - Life in the Slow Lane
Good post Zig. Now if I had the chance I would talk to the locals at a fly shop first . Now if that wasn't the option then I would pick up some rocks ,look in the vegetation to see what was there for fish food. second look to see if anything was coming off the water. .Study that water looking for clues. You said there were no rises so i would go to a streamer type pattern . Why because for one there are always bait fish ,crayfish leaches in most ponds . Plus you can cover a ton of water . Second a nymph bead head . Something to get deep another searching bug. Scud patterns . Depending if any bugs are coming of the water you could determine the type of mayfly nymph to use. Then when all else fails dynamite works every time. 
Ziggy,
As we talked about, ponds scare the you know what right out of me 
I'm a river guy, call it playing safe if you want. At least in a river I'd be able to read the current, structure, etc and konw where the fish will be. Anyway, to your question, I'd probably look to see if baitfish were present, and if so maybe try a streamer. For fall and with some brookies present, maybe a Wood Special, or a Micky Finn. Besides that I may fish a dropper setup with a hares ear/pheaseant tail setup. Cast, let sink, slow retrieve.
-Nic
You approach a new to you Trout Pond , you know for a fact there are Brook trout, Brown Trout, and Rainbow Trout in the pond but see no top water activity ? What is the 1st fly you try and why? How do you contuinue to fish the pond ? Do you have certain type flies you use to scout a pond so to speak? Setting is this: Early Fall, water temps mid 60's , early morning.
+Hunting and Fishing "Thats What I Do"