Thank you both for your comments and to John for some very helpful links
Some of them I am already on, but there were some interesting new ones.
I am waiting to recieve my son's past coursework which should hopefully be today, then I intend to formulate our plan of attack. He has less than a year before his exams so I do need to get this together (initial framework at least) ASAP.
As for tutors, yes, we will be looking for extra help. Although I never considered the option of using tutors as an advisors nor markers and this does appeal.
Thankyou again for your help and advice, if you have any more then please let me know