If you are going to do a JAA IR then you get the books only with the course from your chosen ground school.
Unlike the FAA IR where you can buy the instrument manual self study and sit the exam, in JAA land you have to undertake a course with an approved school who will provide you with there own approved materials.
Most of which is pretty crap, t0o in depth and outdated even for the JAA exams. I used the Oxford Aviation CBT stuff to supplemet the materials I got with my course from CATS.