Why series books? Students love to read books in a series. I have found it is one of the best ways to encourage a reluctant reader to read. Why do students love series books? There are a number of reasons. Which series to buy? Book publishers know that series books are very popular and very lucrative. Take the Diary of a Wimpy Kid series for example. After the first couple books became so popular it was almost guaranteed that each subsequent book would be a huge success. This is a good thing but it can make it hard as a librarian or teacher to decide which book series to invest in. So I came up with a list of some of my favorites to help make your decision easier. I came up with two different book lists. The first list is for younger elementary and includes beginning chapter books.