What?

• What specific content or kind of event do you want to put on?
• What do you want the event to accomplish for the participants?
• What do you want the event to accomplish for your organization?
• What is the event you have in mind going to cost? (You will want to prepare a detailed budget, including all speakers and performers' fees, food and lodging, transportation, equipment and facility rentals, materials, publicity, printing, postage, and any other anticipated costs.)
• What resources (money, materials, facilities, etc.) do you have to work with?
• Are there any sources that might be able to help you with money or material assistance?

When?

• When is a good time to hold the event so it will be accessible to the most people?
• Are there any conflicting events, holidays, or other things you need to schedule around?
• How much lead time do you need to schedule facilities, get publicity out, arrange for speakers, performers, etc., and acquire necessary materials and services?

Where?

• Is your facility easy to find and easy to get to for most people?
• Is it accessible for people with disabilities?
• Does it have the equipment and services you need?

Those pesky details...

• Timing--It's a good idea to work out a timeline when you start, so that everyone understands what has to be done when and how their part fits into the whole.
• Publicity--What is the best means of reaching your target audience? What publications do they read, and can you afford to advertise there? Where do they go regularly that you can post flyers? Can you borrow or buy a mailing list, or include a flyer in someone else's mailing?
• Money--Is there anyone who might co-sponsor your event and lend financial (or other) support? Will cash flow be a problem (that is, will you need to pay for things before the anticipated income comes in?), and is there someone who can loan you startup costs?
• Follow-up--After the dust settles, it's important to get together with your group and evaluate the event. What went well? What would you want to make sure to do again the same way next time? What could have gone better? What would you recommend doing different in the future? Write it all down for future members' reference. Don't forget to give yourselves the appreciation you deserve for a job well done!