To have any hope of doing well in the exam, you must know what is on your syllabus. I have listed the main exam boards websites here
AQA A and AQA B
Edexcel and Edexcel Salters Horners
OCR A and OCR B
Huge revision site covering a wide range of subjects. Good for both revision notes and multiple choice questions
Useful site with loads of quick revision notes, especially for those doing WJEC physics
The Physics Classroom
Nice cartoony site with a fair amount of physics information
Science Course info and revision site
A school website with some online revision sheets
Learning Physics-Post 16 revision
No actual physics information, but helps you with exam strategy
Cranbrook Physics Department
Includes a useful glossary, and links.
General information Links
Great physics information site, that is cleverly set out.
Features a search engine
AS/A2 Physics Links
Directory with loads of links. Covers all sorts of topics
Intute: Science, engineering and technology
Great if you want to look up a particular topic
The Laws List
A long list of physics laws!
Type in your question and people who may or may not know anything about physics will answer it for you!