A tutor can help you hone your reading-comprehension skills. Also, to get the most out of what you read, use the SQ3R method to help you process and remember what you read, the 24-Hour Rule and the links below as resources:
How to be a Successful Student: Reading Comprehension This guide also includes the Power of Positive Thinking and How to Identify your Best Learning Styles.
University of Connecticut: Reading Comprehension This University of Connecticut site on literacy presents the different aspects of reading, such as vocabulary, text comprehension and comprehension strategies.
The Resource Room This helpful site includes comprehension exercises (one uses Harry Potter and The Sorcerer's Stone as an example) and different tips such as Identifying Main Idea.