High way code - DSA - Book shop, Halfords
Know your traffic signs - Department of transport - Book shop, Halfords
Learn to drive - Haynes - Halfords
Pass your driving test - BSM - Book shop
Test Questions - BSM - Book shop
The official driving manual - DSA - Book shop
Now there is a lot of apps available to help with your theory. Please make sure you buy the apps as the free ones are not good enough to get you through your test. Best app is the one with hazard perception, theory and Highway Code all in one