there is somone ( Derek Davidson ) I think ? who advertises, in the aviation mags, although, I believe he's location is south coast
another alternative is the CD learning packages that Oxford Aviation supply
I purchased " Practical Flying Training " and "Airlaw" at Kemble, and I must admit, the explanations coupled with visual display, makes it a lot easier to understand, They are expensive, so I would suggest, buy just one, and see if it suits you !
good luck
TV