I usually give about 10 to 12 star parties a year. Eighty percent (80%) are free to youth groups, scouts, church and school programs. The secret is to make it informative but not too technical. Make it fun, but not a playground. (Equipment is to expensive for horseplay). Involvement is the key to keeping a bunch of kids interested. I print star maps from any of several software kits that are available to give to each participant. Having them identify some of the major stars and constellations makes it fun and interesting.
Always start out with some of the more "faint" objects (like star clusters, nebula's, double stars, etc.). Have them find the objects on a star chart. Next you want to hit them with the planets (depending on what's out there). Always leave the best for last. Pick one of the best (Saturn's rings, Jupitur's moons, the Orion Nebula, etc.) and leave them thinking "WOW"!
Now, of course, if you're in a light polluted area (most are), you may only be able to show a few objects. You may want to show only planets or have a "Moon Party". It's easy to make kid's eyes light up. If you have a moon map, let them "find" the crator that you're showing them in the scope. Let each persons find their "own" crator.
During the day, it's always fun showing sun spots. ALWAYS USE A PROPER FILTER! Use a low power lens so that they can see the whole star, then drop in a 10MM or Barlow and let them look close up. Now all of this is fine when giving a party to kids, on lookers or passers by. Family and friends are a different story. All they want is to "see the neat stuff". Star parties can be big, small, day or night. Make them fun. "If you can take a dozen kids and just get one of them interested enough to continue the interest in astronomy, you have done your job."