Purdue University has recently published a free online Service Learning Reflection Journal. This could be a very useful tool, particularly for those new to service-learning. It offers some reflection prompts and exercises to assign for students. Reflection is an integral piece of the service-learning experience, as it often ties the service to the learning for students.
The journal is available for download here.
Sass, M. (2013) Service Learning Reflection Journal. Purdue University Learning and Service Engagement series. Center for Instructional Excellence: West Lafayette, IN.