The most difficult part about engaging young readers is to get them interested in reading in the first place. Book series have been one way to hook readers into wanting to read more. Any teacher who has spent time in the classroom in the last 5 years knows the power the Hunger Games series has had over young readers (some adult non-readers even picked up reading again because of that series). I have seen classes get hooked on that series together, or students individually burning through the books and eagerly awaiting the next installment in the series.
The following is blog post from the International Literacy Association's Literacy Daily. Carolyn Angus highlights a number of popular boox series for readers of all ages. What I like about this post is that it isn't repeating the same series that teachers see over and over in their classroom. Also, these series go beyond the middle school sci-fi series, Carolyn shares with us series for children as young as 4.
Take a look at her blog post, maybe some of these book suggestions are ones that you think will hook your readers.