This is by no means an exhaustive treatment of the topic, but I have prepared some helps that may assist you or those you work with in guiding a solemn assembly. I'm attaching a file developed in conjunction with other Southern Baptist prayer leaders.
How to Lead a Solemn Assembly
The link below is to an album with 8 video clips about solemn assemblies. Feel free to share with others as you may be led.
About this album:
"Solemn assemblies are times for God's people to renew their covenant relationship with Him. This series of videos by Claude King is designed to help spiritual leaders understand the meaning and nature of solemn assemblies. Claude also shares insights on ways leaders can facilitate a people in their return to the Lord through a solemn assembly. If you have questions, go to his video blog at www.lifeway.com/growingdisciples and post a comment or question."