Organizational tips for childrens home library?

We have our books sorted by topic, or series. Our series collections are alphabetical by author's last name. For example we have all the DK books in one place and all the Osborne books in one place. They usually have the topic written on the side. (We don't have them with the front facing out- just shelved). There are some labels on certain things. We have a HUGE collection of autism resources (we should start an autism book store, I swear) and it is labelled with dates because autism research goes gets old really fast. Certain other books have labels on the shelves too. We haven't cataloged them though. I don't see the point really because I can find things easily.