I know is's a little old fasion, but both my girls loved reading Dick and Jane when they were beginning to read. It gets harder as you keep reading and only introduces a word or two at a time and keeps repeating words from the first page. They had a hardcover where it was long and got much harder toward the end, so they were reading much better by the end. Plus the stories are funny to a three year old...not so much a 5 or 6 year old.