Here are a few sites I've found with some good ideas using Cuisenaire Rods. We just started using Miquon Math (since my oldest is really struggling, and I'm hopeful this approach will help). Enjoy playing!
Cuisenaire Rods: Space, Color, and Mathe
Cooking with Cuisenaire Rods
Introduction to Fractions (5th grade lesson plan)
Play with the Rods online
Cuisenaire Fractions Lesson
Math Perimeter Problem Solving