Moose is excellent eating - I've had moose shot between August 15 and the end of October, calf, dry cow, young bull, old bull and this one from last year which my friend shot at the peak of the rut:
They were all excellent eating, although the bigger rutting bulls take a bit longer to cook. I threw a couple of chunks of ribs and brisket into the smokehouse for ~8 hours or so and then into the oven at ~290 for another 7 or 8 hours in a cast iron dutch oven and it came out like this:
But one thing you really must do after getting one on the ground is get that hide off ASAP! The thick skin and hair retains heat very well and the meat can spoil quite quickly in warmer weather.