Hi Andy
Best advice is plan ahead. Qtr or 3Qtr is good for showing up details on the Lunar surface. You could even try pointing out where Apollo 11 landed. I usually do the Moon either first or last (most often) in the session. Planets are always good especially Jupiter and Saturn - Saturn will be the one thing most of them will remember looking at in 20-30 times. Venus can be good when it is waxing/waning - good evidence for heliocentric solar system.
Alpha Centauri - showing two of the stars that make up the triplet.
Albireo - another good binary to show how stars have different colours based on their temperature.
You can check Australian Sky and Telescope for their take on monthly highlights for viewing.
Here's a brilliant website that has monthly sky charts that can be printed off your viewing audience.
http://www.skymaps.com/
A set of constellation cards can be found here:
http://assa.saao.ac.za/how-to-observ...arts/concards/
(Sky Safari is also a great app for what's up and good to look at).
Here's a link for a very simple planisphere - it needs to be printed out on A3 card - A4 is usable, but a bit on the small side for young kids. Get your Guides to do this as a lead in activity and bring them along on the night.
http://www.docdb.net/downloads/ssw/ssw-v08.pdf
(This is the planispheres home website:
http://www.psychohistorian.org/)
I'm sure that other IIS members will add to this list for your - it will be a full on night and you'll be flat out viewing objects and answering questions - but it will be a really worthwhile endeavour for those who attend and yourself.
Last thing - plan your viewing - planets first? stars? objects by transit time? all up to you.
Enjoy!
Paul