There is your best bit of control. Set the limits on what file type(s) are submitted. It would give you less headaches.
Head over to the Scribus and LibreOffice forums. There are others that had similar projects that can give you tips there.
Easiest tip out there, if this becomes a large project, break the layout into several parts. This will keep the project from overwhelming the resources on your computer. I’m assuming that images are to be included? Color space issues could crop up. try and keep it simple. Use styles as much as you can. this will make changing the look easier if need be.
Hunt around for layout examples on the net. you will learn lots from them.
Oh… one really big check to make… That the recipes are actually tested! You may want to require a sampling! 
(Free Grub!)