Originally Posted by Flyingmouse
Secrets of Droon?
DS picked the Droon series up immediately after MTH series.
The next was the "Flat Stanley" series.
I believe the next ones were the Ron Roy Mystery series : http://www.ronroy.com/books_atoz.html
and then the "Heroes in Training series" - http://www.simonandschuster.com/series/Heroes-in-Training