I just read all the answers to this wonderful thread and found the feed suggestions very informative and interesting.
I have 20 Black Australorps and have been raising them for 12 years. Also have 4 roos. I live in Northern California, so our weather is quite different than that of the cold climates. However, our winter temps range from 32-45 at night.
I have been using a winter light for most of my chicken experience here. It's on a timer to come on at dusk and off at 7-8pm and on at 5am and off at 7am depending on the length of our days - I adjust it monthly so that it's on for about 12-14 hours/day. It's off come Spring until next winter.
I've always fed 16% laying pellets or crumbles. I've always found they lay more when I give them our left over white bread. Weird. They go absolutely crazy over it. They do get salad scraps and vegetable peelings. But, they really love their white bread.