I've heard a lot about the Domesday Book, but it just doesn't seem very important. I also know that William I wanted to keep the laws as close to the original laws of England.
The actual words which he used were that all things should have "the laws of King Edward in lands and in all things, having added thereto the things which I have appointed for the welfare of the people of the English."
(Quote from The Life and Times of William I by Maurice Ashley)
I've heard a lot about the Domesday Book, but it just doesn't seem very important
Allow me to disabuse you of this notion. The Great Survey, called the Domesday Book from the 12th century onward, is not only the model for every public record that came after it, but also the most comprehensive and important work that we have about land and property in medieval England.
The point of the survey was to find out what taxes were owed to the crown, what the produce of the crown's lands was, and to find any other miscellaneous fees the crown might be owed. As such, literally everything down to the last sheep or cow in much of England and part of Wales was recorded. (Being a new ruler, William wanted to know what his new land would produce and support, and also saw the obvious administrative advantages of having a list of all his lords and tenants.)
You can find a free online copy of the book here, if you're interested in the kinds of records it kept or interested in looking up a certain plot of land: http://www.domesdaymap.co.uk