Chicken of the Woods (Laetiporus sulphureus)
This time of year it's common to come across the "fruiting bodies" of fungus, from giant puff ball mushrooms to beautiful shelf fungus. One of the most common types of shelf fungus you'll see are Laetiporus sulphureus mushrooms, often called "chicken of the woods" or "chicken fungus." They are edible fungus with bright yellow-orange coloration and a white edge. You can be sure of your identification if the underside of the fungus doesn't have gills, but small pores. Of course the usual cautions apply, make sure you know it is truly edible before you eat it! The brackets of these fungi can be up to about 5" each and collectively they can weigh several pounds. The younger the fungus the more yellow it is. As the fungi age they turn more whitish. The softer and more yellow the fungus the better it is for eating!
You can prepare this fungus like you would any other edible mushroom, and it's often considered a good replacement for meat because it has a chicken flavor. You can also freeze these mushrooms for several months before eating, which makes them a great addition to family meals throughout the winter (or for Thanksgiving dinner). If you harvest them during the early fall, leave behind the base of the shelf fungus and you should be able to harvest another generation before winter.
A caution for home owners. If you see the fruiting body (edible bits) of this mushroom then you're likely to lose the tree that it's growing on. Chicken of the Woods is known for it's dense mycelium (root-like network) that penetrates the heartwood of trees and cause brown heart rot. If the fungus is fully mature, and producing bracket fungus, then it's likely the tree is on its way out.
Here's an interesting Youtube video about how to harvest and prepare the fungus: http://www.youtube.com/watch?v=S9ieYUKlJ_w.