Make sure all the people and equipment will be available when you need them. You may need a 'shooting schedule' that lists when you will shoot each scene and what you will need.
Before you start filming, get permission to show the film from people who appear in it (or their parents, if they're under 18), particularly if you want to put it on a website. There's a printable permission form on the CD.

Guidelines - Even with permission, you should make sure that any version that's published on the Web doesn't give the full names of children who appear in the video.