Theory Test:
Book: https://www.gov.uk/book-theory-test
Change: https://www.gov.uk/change-theory-test
Cancel: https://www.gov.uk/cancel-theory-test
Driving Test:
Book: https://www.gov.uk/book-driving-test
Change: https://www.gov.uk/change-driving-test
Cancel: https://www.gov.uk/cancel-driving-test
How to prepare for Theory Test?
You can buy all of the materials in Halfords, WH Smiths, amazon, ebay or just order them from DSA website:
Theory Test Kit: http://www.dsabooks.co.uk/product_info.php?products_id=297
Hazard Perception olny: http://www.dsabooks.co.uk/product_info.php?products_id=235
Theory test only: http://www.dsabooks.co.uk/product_info.php?products_id=296
Moreover, now you can learn on your smartphone using app: http://www.safedrivingforlife.info/shop/product/official-dvsa-theory-test-kit-app-app?&trackid=005503
You can do MOCK TEST online: http://www.safedrivingforlife.info/take-official-free-practice-driving-theory-test/