The Domesday Book offers great insight into life at the time of the Norman Conquest. When you read through the records contained in the Domesday Book, you run across a great many terms which may be confusing, such as 'bordars', 'geld', 'hundreds', and so on. This short glossary of terms is intended to help you better understand the terminology of the Domesday Book.

As for the actual book, there are several paid versions online, but as of this writing, no free access to a complete translation. The best hard copy version that I'm aware of is the one I use: the Penguin Classic, 'Domesday Book; A Complete Translation' (ISBN 0-141-43994-7). You can purchase a copy through here.

The Norman acre was a unit of measure of both length and area. It was defined by the length and width of a furrow -- 40 by 4 perches. This was by no means a standardised measurement as a perch varied in length. (see 'Perch' below) However, assuming a perch equivalent to 16.5 feet, a Norman acre could theoretically match the size of a modern acre of 43,560 square feet: the equivalent Norman acre would be 660 feet long and 66 feet wide. 
An acre could be used as a value to assess geld, with 120 acres equalling one Hide.

Land held by right of freehold.

A measure of land used for vineyards, originally 100 square Perches.

An outlying estate

Land given by royal charter.

A peasant of low standing. This term was on the way out, to be replaced by 'Villan'.

A peasant, lower on the social ladder than a Villan.

One-eighth part of a Carucate.

The obligation of providing carts for the transportation of a Lord's goods.

An area of land equal to the amount that could be worked by a team of eight oxen. In some areas, the Carucate was the measure used to assess geld, instead of the Hide.

A free peasant, with a Wergeld of at least 200s.

A cottager, similar in status to a Bordar.

Land in the personal possession of a Lord, used to support that Lord rather than the tenants working it.

A free man holding land in exchange for personal service. Used primarily in Yorkshire and Lancashire.

Free Man
A landholder of non-noble status. Freemen were often in the command of a Lord.

A settler from abroad (not necessarily French) of non-noble status. Frenchmen were freeholders.

A unit of measure equal to the length of a ploughed furrow, or 40 perches long.

Tax, assessed per hide.

The standard unit of land measure, used to assess geld (tax). In theory each hide was divided into four equal parts, called Virgates.

The largest administrative division of a Shire. The Hundred was nominally 100 hides, but in practice the size of a Hundred varied widely from place to place.

a measure of distance, 1000 paces in length, or roughly 1 1/2 Roman miles. In the later medieval period the league was equal to 12 Furlongs, whereas the mile was standardized at 8 Furlongs.

An estate. Manors could be vastly different in size, and might have an official lord's residence, or castle, at its centre.

Usually a corn mill for grinding grain, powered by water. Windmills did not come into use until well after the Conquest.

A measure of land varying from 14 to as much as 28 feet.

One way of assessing the value of an estate was to estimate the number of eight-ox plough teams needed to cultivate the land. Thus, a Domesday entry might say a 'Then as now, 2 1/2 ploughs", meaning that there was enough land on the estate to require 2 1/2 ox teams to work it. This measure could also be used to assess the value of the estate for taxation.

Literally, 'riding man', a servant who attended his lord, and often rode escort.

A payment (usually payment in kind, such as livestock or grain). Render was sometimes used to determine the value of a manor.

The right to administer a given place and its people

A free man owing service to the Lord of a Soke

The royal official in charge of a Shire. The Sheriff was responsible for financial and judicial administration, as well as overseeing royal castles and estates in the Shire.

An administrative district, roughly equivalent to our modern county. The term Shire might also refer to the Court of that county.

Shorthand for the Latin phrase Tempore Regis Edwardi, which translates loosely as 'In the time of King Edward'. Generically used to indicate the state of things before the Norman Conquest in 1066.

The nominally free inhabitant of a village, a villan (or villein) was better off than a bordar.

A measure of land equating to one-quarter of a Hide.

A combination of Old English terms meaning 'man money', the wergeld was originally a sum of money paid by the kin of a man who had killed another to the deceased man's kin. The payment of a wergeld was supposed to avoid blood feuds. The actual amount paid depended upon the social status of the dead man.

A note about Administrative districts
For the purposes of taxation there were essentially three levels of administrative districts in Norman England. In descending order of size and importance these were the Shire, the Hundred, and the Vill, corresponding very roughly to our modern Counties, local districts, and towns/villages.

Domesday England map