Preparing for the SSC CHSL (Staff Selection Commission Combined Higher Secondary Level) Exam requires a systematic approach and the right study materials. Here are some of the best books that can help you in your preparation:

1. Quantitative Aptitude:
- "Quantitative Aptitude for Competitive Examinations" by R.S. Aggarwal: This book covers a wide range of topics with detailed explanations and ample practice questions. It is highly recommended for building a strong foundation in quantitative aptitude.

2. General Intelligence and Reasoning:
- "A Modern Approach to Verbal and Non-Verbal Reasoning" by R.S. Aggarwal: This book is a comprehensive guide for reasoning and covers both verbal and non-verbal reasoning topics. It provides ample practice exercises and solved examples to enhance your logical thinking skills.

3. General Awareness:
- "Lucent's General Knowledge" by Dr. Binay Karna and Manwendra Mukul: This book is a popular choice for general knowledge preparation. It covers various subjects like history, geography, polity, science, and current affairs in a concise and comprehensive manner.

4. English Language:
- "Objective General English" by S.P. Bakshi: This book covers all the essential topics of the English language required for the SSC CHSL Exam. It provides ample practice exercises and previous year's question papers for practice.

5. Descriptive English:
- "Essays for Civil Services and Other Competitive Examinations" by Pulkit Khare: This book is specifically designed for descriptive English preparation. It contains a collection of essays on various topics along with tips and guidelines for effective essay writing.

6. Practice Sets and Previous Year Papers:
- "SSC CHSL Tier-I 10+2 Solved Papers" by Kiran Prakashan: This book provides solved papers of previous years' exams and practice sets for thorough revision and understanding of the exam pattern.

7. Online Resources:
Apart from books, you can also utilize online resources such as EduRev's SSC CHSL Exam preparation material. It offers a wide range of study materials, practice quizzes, and mock tests to help you prepare effectively.

Remember to create a study plan, revise regularly, and practice as many mock tests as possible to improve your speed and accuracy. Good luck with your preparation!