Below are some useful resources for learning more about empathy:
The Social Neuroscience of Empathy (2011), edited by J. Decety and W. Ickes
Here is a 1-pager on empathy
Below is a resource on creating a successful group:
Skills and Techniques for Group Work With Children and Adolescents (1995) by R. Smead
Click here for a summary of best practices adapted from Smead's work.