Firstly, if you doing Civil Rights on the Edexcel exam board at AS level then you should consider buying this book. It's very useful because it's not loaded with detail unlike some other topic guides, as the format is nice and easy to break down and put into note form.
However, I would also strongly recommend buying the book "Civil Rights in the USA 1945-68 (Access to History) (Paperback)" as it contains and covers more things with more depth, it also is easy to break down with diagrams useful for revision on every other page. The "Study Guides" at the end of each chapter in the book are example questions that might come up in the exam (there example questions for OCR, AQA and Edexcel exam boards. Ive literally just come out of my history exam and this book was INCREDIBLY helpful in combination with the book I'm supposed to be reviewing! It can also be used as a cross-reference with it too.
So my recommendation is that you buy this book in combination with Civil Rights in the USA 1945-68 (Access to History)
and your knowledge will be as sound as a pound!