The best preparing method for all exams is to solve the past papers of the exam
Analysis of the AMC 8 revealed that there are 81 item types in the test.
This book, Past Papers AMC 8 vol.1, contains
12. Percentage
13. Polygon
14. Number Analysis
15. Counting Principle
16. Table Analysis
And this book provides correct answers and detailed explanations. In addition, by providing item types for each question, students could make feedback based on incorrect answers. Practice like you test, Test like you practice