Even if your child knows how to read, or is learning to read, you can both benefit from reading together. Reading aloud gives you time together, and your child can ask questions about the story you are reading if needed. You can also ask questions about the chapter or segment you read, or the story so far, to get an idea of what your child is retaining. One of the best things about reading aloud is that you can revisit favorite books from your own past, and introduce beloved literary friends to your child.
Below are four great books to read aloud:

Frog and Toad Series by Arnold Lobel
Read to: ages 3-8
This early reader series features Frog (a frog), and Toad (a toad), and their adventures. Frog and Toad have distinct appearances and dispositions. Frog is the more mature character, and often helps solve problems for the more flighty and sometimes grumpy Toad. Chapters are easy to read, and the stories have gentle humor. Frog and Toad are good friends, and support one another well. Mouse Soup by the same author is a great pick as well.

Little House on the Prairie Series by Laura Ingalls Wilder
Read to: ages 5+
The "Little House" books have been loved by generations of girls, if you are a mom, chances are you read this series in your youth. The books recount the author's childhood in the pioneer days of our country, the late 19th century. Read these in order, if you can. The Little House books will introduce your child to a different time and place, and a different style of living. There are some dramatic moments in the books, but nothing terribly scary. If you child enjoys these books, there are several Little House themed cook and activity books available as well, so you can do projects together based on the stories you have read.

Charlotte's Web by E.B. White
Read to: ages 5+
This book is a classic for a reason. The story of Wilbur the pig, and his friend Charlotte the spider has strong themes of friendship, loss, and hope. Be aware that this story, while compelling and ultimately enjoyable, may be upsetting to sensitive readers. (Read ahead to the ending on your own if you are not familiar with the story). This story is also a great conversation starter when read alongside or to older children. Young children will not "get" all of the underlying themes, but will enjoy the surface story of farm life and friendship.

Harry Potter Series by J.K. Rowling
Read to: ages 8+.
This series is great to read aloud. Even adults without children enjoy the audio versions, as the language is very animated. If you drive your kids to school, consider an audio version for the car-one book should last most of the school year! Begin with the first book, and progress to later books as your child grows. Be aware that the themes in the books get darker as the series progresses. While book #1 is appropriate for most ages, books 4-7 are not really suitable for young readers (though older children and adults will enjoy them immensely).

Other great "read aloud" choices:

The Wizard of Oz by L. Frank Baum
Junie B. Jones series by Barbara Park
Stuart Little by E.B White
A Little Princess by Frances Hodgson Burnett
A Series of Unfortunate Events by Lemony Snickett
The Little Engine That Could by Watty Piper
Indian in the Cupboard series by Lynn Reid Banks
Ramona Series by Beverly Cleary