Our first ever local MMF was in September and a huge success. Our maker group did not sponsor it, which turned out to be a blessing. All the logistics were handled by another group (see http://www.champlainmakerfaire.com), which left us plenty of time to get projects ready. I did a table called “Behold the Blinkies” and had several bright projects on display. I also did a fun DIY art project for the kids, which had a pulsing RGB LED as the centerpiece of a necklace. As Gus mentioned, having stuff for kids to do was really appreciated by the parents. I have even been approached in public more than once by folks who know me now as the “maker faire blinky necklace guy”
My biggest advice is not to over commit your time. That is very easy to do early on, particularly before you’ve fleshed out many details. The biggest regret I have is not having enough time to check out all the other tables, workshops, and special events. We were lucky enough to get some funding for an event coordinator, who did a great job keeping everybody on schedule leading up to the big day. Delegate tasks as much as possible, and utilize volunteers heavily. We gave out tshirts and had a ‘first beer is on us’ social event for just the presenting makers and volunteers. Many of the volunteers were makers in disguise and were there to feel out the scene. They’re now jazzed to bring a project next year.
I could go on and on… feel free to hit me up with any questions via email.
 one more important thing - there is never enough time to plan, so start now. The items we left 'til the last minute were the ones that generated the most bumps in the road.