Some tips for effective discussion planning
 
Plan a discussion, not a presentation.  Design your plan to encourage meaningful participation.
Identify what you want to tell people, what you want them to figure out, and what you want to leave open for discussion without necessarily reaching a single conclusion.
Don’t assume that people will simply answer your questions. Come prepared to have to work to get people to talk.  Here are some strategies that might help:  
Have people write or talk in pairs or small groups first
Go around the room and ask each person to say something from their written notes
Have small groups report on some specific part of their conversations
Direct people’s attention to a specific part of the text – read a paragraph or two and ask people to use that section to answer your question; you can even do this with groups – assign each group a section of the text to work with
Ask specific, focused questions that can help people move toward answering bigger questions
Call on people, even if they don’t volunteer to speak
Make your questions deliberately controversial; play devil’s advocate
Have group members offer contrasting responses, then ask others to say which point of view they agree with and why
Be willing to live with a little silence – sometimes, if you just wait in silence for a few minutes, someone will speak
Figure out about how much time you want to take with each part of the discussion, and assign someone to keep track of time.
Plan a conclusion – what final ideas or insights do you want to leave us with?  Don’t let your session just sort of fade out.