If your child is having difficulty with his/her reading, you need to determine what the exact problem is: phonemic awareness, phonics, fluency, vocabulary, comprehension, etc.. You can either request to have your child test through his school or privately. Either way, you need some insight as to what is happening.
If you are going the school route, here are some steps you can take to get you headed in the right direction.
1. Set up a parent teacher conference with your child's teacher. Ask that the reading coach and/or ESE specialist be present. Discuss your concerns, show work samples, and ask them how to go about having your child tested. Keep in mind that going through the school process can be very slow - taking up to a year.
2. Ask for specific things you can work on at home with your child. A good teacher should know some of the areas of weakness are in your child to give you some direction.
3. Read every day to your child. He/she needs to hear good reading. Go to the library and check out lots of books both fiction and informational. Find a quiet spot and enjoy the time you are spending together.
If you are going the private route, ask around for a good child psychologist or learning/testing center. This can be costly, but the results are much faster. Before signing up for any testing, double check with the school to make sure they will honor those results.
Once you find out the exact weakness and strengths your child has, feel free to post another question asking for strategies and activities you can do with your child to help with reading.