The word bookland does not appear in Domesday Book (though there is one occurrence in the Exeter Domesday satellite text); but its characteristics are believed to have shaped many Anglo-Saxon tenures.
Bookland was land held by book, or charter, in perpetuity. Originally created to endow the Church after the coming of Christianity, royal grants of bookland were by the eighth century being made to laymen and were much sought after due to the royal rights they conferred and the greater freedom of alienation they allowed. By the eleventh century it is likely that most land was regarded as bookland unless there were clear evidence to the contrary. One distinctive survival, however, was sokeland, mostly located in the Danelaw counties. On sokeland, the lord had to the right to those royal dues and renders alienated by a royal book at some time in the past; but he did not own the soil, and his tenants were free to dispose of their property. If they did so, however, the purchaser incurred the obligation to pay the dues with which the soke was encumbered.
For more detail, see Richard P. Abels, Lordship and military obligation in Anglo-Saxon England (1988); Susan Reynolds, 'Bookland, folkland and fiefs', Anglo-Norman studies, vol. 14 (1992), pages 211-27; and David Roffe, Domesday: the Inquest and the Book (2000).