A complete walkthrough of the Edexcel GCSE Maths Syllabus A Higher Tier Paper 2 from June 2012.
See TES Resources for a PDF containing written solutions and individual links to each question on this paper.
It's an amazingly efficient way for students to get individual help on just they questions they are struggling with - if they can't work out how to answer the question from the written solution, then seeing it appear line by line with detailed explanations of each stage will help enormously!
It's ALWAYS a good time to revise for your maths exams!