We had several of these mushrooms come up in a raised bed that was converted into a wood core bed last year. This mushroom grows well on wood covered with dirt, so you should see it popping up in Hugel beds. It's edible, but not a common table mushroom.
Don't eat anything you haven't properly identified. To do this you need books, and you need to know how to make a spore print. I would recommend the Audubon Society's Field Guide to Mushrooms (http://www.amazon.com/National-Audubon-Society-American-Mushrooms/dp/0394519922) . I picked one up at a used bookstore for 5 bucks. (along with several others)
Even with books, it is easy to get the wrong mushroom. Usually not deadly, often sickening. Work with an experienced friend or local mushroom society. There are a few that most people can identify from books: Turkey tails, shaggy manes, and a few others. They are often listed in books as 5 easy mushrooms, etc.
John S
PDX OR