I just found this, haven't been on here in ages and well, I come into this category too.
GCSEs: 3A*s, 8As
AS Levels: Maths, Further Maths (AQA), Physics, History and Gov & Pol
Potential Unis: Oxford (Hahaha), Warwick, ICL, Sussex, Surrey, Bath, Southampton and maybe a few others.
Prep: Ummmm, not an awful lot. I have a books list (Y)