I've helped with organizing 2 off-season events (in DC and in Baltimore), and worked at a few others.
All the resources referenced above are
very useful. Duel on the Delaware has also shared their handbook with us.
Other suggestions:
- Decide why you are having. As a team builder? As a Fundraiser? To help with awareness of FIRST teams in your area? These are just a few. Once your organizing committee decides it will help drive many of the decisions you will have to make about cost to teams, number of teams, when to have.
- Find a sponsor in the community willing to give a donation up front to help cover expenses.
- Figure out the date early. January is good time to decide when in the offseason the event will be held. See #1.
- What field are you going to use? If using a FIRST field, will have to lock this in early. See #3.
5. Keep documentation on everything you do.
Hope this helps.