Sedimentary rocks are formed in places where there has been water at one time. Dead animals, plants, and pieces of rocks or minerals are carried to these places by wind, water, ice, or even gravity.
How sedimentary rocks form: http://www.youtube.com/watch?v=NygkD8uATng&safety_mode=true&safe=active&persist_safety_mode=1
How sedimentary rocks form: http://www.youtube.com/watch?v=NygkD8uATng&safety_mode=true&safe=active&persist_safety_mode=1
The four types of sedimentary rocks are shale, limestone and coal.
http://geology.com/rocks/sedimentary-rocks.shtml
http://geology.com/rocks/sedimentary-rocks.shtml
They are used for gravel and other household things.