In 1086 Burstock was recorded in the Domesday Book as 'Bureuuinestoch', meaning a farm ('stoc') owned by either 'Burgwine' (a man) or 'Burgwynn' (a woman). It had 12 households, 8 acres of meadow and 3 ploughlands. It was in Whitchurch Canonicorum Hundred, the lord was William Malbank and the tenant-in-chief was Earl Hugh of Chester.
Before the Dissolution of the Monasteries in the mid 16th century, Burstock was closely associated with the Cistercian monks at nearby Forde Abbey; at Whetham, in the north of the parish, the abbey developed a mill, and in 1316 the Abbot became Burstock's lord of the manor.
Dorset Research Tips
One of the many maps available on the website A Vision of Britain through Time is one from the Ordnance Survey Series of 1900 illustrating the parish boundaries of Dorset at the turn of the 20th century. This map blows up to show all the parishes and many of the small villages and hamlets. The internal boundaries on this map are the rural districts which are indicated in the "See Also" box for the place concerned (unless it is an urban parish).
The following websites have pages explaining their provisions in WeRelate's Repository Section. Some provide free online databases. Some are linked to Ancestry.