Select books on the appropriate reading level. If you need help determining your child's reading level, ask his teacher.
Read aloud often. Reading aloud will help the student hear mistakes and learn how to develop meaningful reading rhythm. Stop your child at problem points and discuss what went wrong.
Stop after each paragraph and discuss what it means. Not only will this help your child determine what the author is trying to say, but it will also force the child to think about what she's reading.
Ask questions that require your child to use clues from the story to draw conclusions and make predictions. Meaningful questions that can't be found directly in the text ensures that your child flexes critical thinking brain muscles.
Point out unknown words. Help your child use context clues surrounding the word to try and find meaning. Also draw attention to useful prefixes, suffixes, and roots in the word.
Help your child make connections between what happens in a story to things that have happened in real life. Also attempt to show connections between different stories.
Read often. Practice may not make perfect, but the more you read with your child, the more they will get used to it and develop critical reading skills. Reading often also helps increase vocabulary.