We ate our first cockerel last week, so I can't offer loads of experience on the matter, but this one was delicious.
The bird was over 6 months and totally free range.
I looked up 'coq au vin' recipes online and adapted that concept of a slow cooked pot roast with liquid a bit to suit what I had to hand on the day. I just cooked the bird whole.
Basically I sizzled up some thick strips of bacon, added the whole bird to the fat to brown on all sides, added white wine, honey, spices (thyme, cumin and bayleaf) and some carrots, put foil under the lid for an extra seal and put it in a lowish oven (180C I think) for about two hours. If your range cooker is not as hot I would just leave it cooking for longer.
I checked twice to make sure there was still enough liquid in there (you definitely want a couple of cm of liquid in there at all times, probably more to start with, if the sauce is too thin at the end you can boil it down a bit, but I didn't have to).
Let it rest for a while before cutting it up - it practically just fell apart into portions by itself. The leg meat was very dark but delicious, neither tough nor dry. We got 3 meals for two out of it.
Can't wait to do the next one now!