The geology of local landscapes and small scale features
(this is consciously the start of the answer - my regional geology books -cf. above comment, are packed away due to a house move).

The rolling hills are very distinctive of the English Jurassic &amp; Cretaceous. Relatively low dipping rocks - long wavelength folds. The ridges are due to rocks that are more resistant to erosion. For example, the English chalk forms the North Downs and South Downs (and the Yorkshire &amp; Lincolnshire Wolds). Chalk is actually more resistant to erosion that some of the surrounding rocks (don't believe me? Have a look at Beachy Head or Flamborough Point!).  These ridges have influenced pre-Roman history - eg. the Ridgeway follows a series of these ridges.

I may be out of date on this, but the folding is usually blamed on the formation of the Alps. The Alps are a long way off, but their influence can be felt as mild folding. The cause must be after the youngest Cretaceous that is present (which I think is the chalk?) - and there was only really the Alps, the Paleogene North Atlantic Volcanism (eg. Skye, Arran, Mull), and opening of the North Atlantic to choose from.

As for your soils: This is where the Regional guide will help. The soils are much more recent. A decent explanation will probably involve at least one ice age, and river courses which have since changed (eg. the proto-Thames used to flow from the North!)