As a successful TA, you need to often host small group discussion and study groups to help the students in your class. Here are the strengths, limiations and preparation pointers.
STRENGTHS: 
- allows participation of everyone 
- people often more comfortable in small groups 
- can reach group consensus 
LIMITATIONS: 
- needs careful thought as to purpose of group 
- groups may get side tracked 
PREPARATION: 
- needs to prepare specific tasks or questions for group to answer