Check for some mycology clubs or organizations in your region. They can point you in the right direction as far as good reference material and local variations. One of my favorites is- http://www.amazon.com/National-Audubon-Society-American-Mushrooms/dp/0394519922
Combined with their field guide to trees and your own knowledge of the outdoors, and you should be well on your way.
It has been a great enhancement of my and my families life, providing countless hours of healthy fun and some of the best food experiences in the world.
You don't want to go about it uninformed though. That destroying angel is one of many with a very common appearance that can wipe you out.
I stick mainly to ones that are easily identifiable with virtually no chance of confusion.