This tool from the Chicago Public Libraries helps you pick books that match the reading skill your child is working on. You can find and borrow these books from your local library to help them practice.
For example, if your child is working on three letter words like cat, dog, and dig, you should click on the “Consonant-Vowel-Consonant Words” link and see what books are good for practicing those skills. Or, if your child has already learned three letter words, but is needing practice with longer words like click, flick, and ship, then you should click on “Blends and Digraphs” to find books that help with those types of words.