There have been many field guides to spiders over the years and most are really good. Of the more than 49,000 species of spiders worldwide, some 4,000 are in North America. Spiders of North America explores more than 500 of the most common and interesting spiders found in this region of the world. This richly illustrated guide begins with an overview of spiders―what they are exactly, how they can be found, how they develop, and why they are important.