Past experience has taught me that the folks at the county extension office weren't going to be too successful at identifying the mushrooms overtaking my yard. They are nice people and try to be helpful, bless them, but I can thumb through antiquated books with a blank stare on my face with the best of them.
So when some of the shrooms tripled in size overnight, the finding of information became a more pressing concern. Would the dog turn purple and swell up like a balloon if he sniffed one? Would the girls shrink and carry on conversations with caterpillars if they licked one? Then I found these lovely people over on the forum at http://www.mushroomexpert.com/ and quick as a wink they had several of my monsters identified. The whoppers above and the small, cottage cheese-like ones in the last post are both types of puffballs, and are edible. Cream of mushroom soup anyone? Me neither. But it is good to know that I don't have to worry about them. The others look like the common ones that you see growing in mulch and they are already drying up.
The internet may have it's draw-backs, but I love how quickly you can find the information that you need on any given topic from British pipe fittings to the micrathena gracilis. Now you know you won't be able to sleep until you look that one up!