Besides the great help you will get here, I have listed a few additional resource websites. And, don't forget to scan through some of the previous messages here.

Planning A Family Reunion
http://homepages.rootsweb.com/~homespun/fr9.html

Reunions Magazine
http://www.reunionsmag.com/

Family Reunions - Celebrating Your Roots
http://www.aagsnc.org/articles/reuniontips.html

genealogy Forum - Reunion Planning http://www.genealogyforum.rootsweb.com/gfaol/reunion/PlanReun.htm