Orderic Vitalis is one of the first wave of post-Conquest "English", born in 1075 to a French father and (presumably) an English mother. His Historia Ecclesiastica , especially the second book, deals somewhat with this new concept of English identity and the transfer of power.

William of Poitier's Gesta Guillelmi might be of use to you as well, as might the Anglo-Saxon Chronicle.

Domesday Book has lots of information about who owned, or rather, who held land, and who formerly held land in the same area. This gives, with some analysis, a snapshot of how many landholders were still English, certainly in the lower echelons of the land-holding class.