Page about Woodbury, includes an extract from Aileen Fox’s “Prehistoric Hillforts in Devon”, and a link to the Clinton Estate pages, which also have a page about the castle.
hrothgar
Bournemouth University site contains some photos, plans and summary of its archaeological history.
Dolbury is in the grounds of Killerton House, owned by the National Trust, this site has details of opening arrangements, transport links, contact details etc.
[Thanks, Green Oak, for the updated link. TMA Ed.]
This Bracknell Forest Council site contains a link to a PDF of their leaflet for the barrow.