I did not find that book helpful at all. Use these links:
Everything you will need to know is covered in these links. Take the math test and see how you do, and it will also help you know where you need to study. They also give you subject matter to know.
They helped me more than anything in the overpriced HESI study guide.
Depending on what you have to take, you will have up to 4 hours to complete the exam. The subjects are Chemistry (25 questions), Biology (25 questions) Anatomy and Physiology (25 questions), Math (50 questions), Reading Comprehension (25 questions), Grammar (50 questions, I think) and Vocabulary (50 questions, I think).
You can take the subjects in any order. You can take as long as you like per question, as long as you finish the entire test in the allotted time.