Camera
Before you film anything, familiarise yourself with your camera and read the instructions so you understand how most bits work.
Practice using the camera, and get your camera crew to do likewise. The better you know your kit, the more comfortable you will become. With small domestic cameras, getting in and out of the menus can be fiddly and takes practice.
Even if you don't need a certain button, it is great to be able to respond, when someone asks the inevitable 'what does this do?'
The principles of video use are very similar to photography, if you have experience of taking photographs you will find many of the issues such as exposure, framing and lighting the same.
Encourage good habits: Put all kit away carefully, if everything has a place you are more likely to spot when something is missing. Get batteries onto charge, check lenses are clean, etc...
For me, movies should be visual. If you want dialogue, you should read a book