There are a lot of Early Reader series out there. If you don't know what I mean by "Early Reader," they are the books that often have a number on the front (usually 1, 2 or 3) and are about 48-54 pages long. Think Cat in the Hat.
It has been a long time since Dr. Seuss wrote some of the first Early Readers. Just about every publisher has a series now. There is even an award given by the Association of Library Service to Children for excellence in this category of writing for children named after Theodore Seuss Geisel himself.
These books are great for children who are becoming more independent in their reading. The vocabulary is basic and the format is easy to follow. And there are some authors who are really dedicated to making these books fun for kids. Mo Willems' "Elephant and Piggie" series and Ted Arnold's "Fly Guy" series are two that Isaac loves.
Unfortunately, as often happens when companies see a niche that they think they can capitalize on, the number of Early Readers has exploded. Some are okay, others are so boring they are painful to read, and then there are the rare gems. The real problem is that there is no standard in the leveling of the books. 1 is, obviously, the easiest level, with 2 and 3 getting progressively harder with more difficult vocabulary and longer sentences. But one publisher's "1" may be another's "2," and a level "3" from one company may be off the charts hard for the children they are targeting, usually 1st and 2nd graders, while another's is much easier to read. The artwork in most Early Readers also tends to be less polished and uninspiring than the illustrations in more traditional picture books.
There is one series that I really do like, even though the books tend to be a bit difficult for the intended audience. National Geographic has a non-fiction Early Reader series that Isaac and I have checked out of the library on our recent visits. As with most National Geographic publications, the photographs are stunning. We have read some of the animal books and the information is engaging for children and well-written. Non-fiction books can be hard to fit into the Early Reader category because the amount of information that you can get into 40-50 pages with low-level vocabulary is limited, but these books are packed with facts. Even if they are not being read cover to cover, these books are beautiful to look at.
Time For Kids also has a non-fiction Early Reader series that uses photographs and contains a lot of information. The Time books are also more accurately leveled.
Isaac loves reading about animals, as do many little boys. Soon he will be reading on his own. I am glad there are books like these out there that will interest him.