If you want more sentence structure practice and haven't tried Rags to Riches yet, go here:

http://www.quia.com/rr/126726.htmlhttp://www.quia.com/rr/126726.html

Here's another site:

http://www.proprofs.com/quiz-school/story.php?title=sentence-structure-simple-compound-complex-compoundcomplex-sentences

This one is a bit simpler (but pretty cute). It doesn't test compound-complex, but it will help you review simple, compound, and complex.

http://www.harcourtschool.com/activity/sensort/index_pre.html