Well, that depends on the size of your yard now, doesn't it. One cubic yd of mulch will cover a little more than 300 square feet to a depth of one inch. It will cover 108 sq. ft -- about a 10' x 10' yard -- to a depth of three inches. Happy mulching!
Need more information? Newspaper archives are one of the best online research tools. If you're searching for information on people, try Intelius.