Virtual Salt
Virtual Salt: Word Roots and Prefixes
At this website, there is a large chart that "Contains some of the common roots and prefixes that make up the building blocks of numerous English words." Columns for roots/prefixes, meanings, and examples are included.
Able Media
Ctc Web: Latin Derivatives Exercises
These teacher-created exercises use amusing stories chock full of Latin derivatives to help students connect ancient and modern languages. Unfortunately, there is no key.