What is the best way to create an online interface for generating PDF files based on a predefined template?

I want to design a Newsletter template for a local committee that I am on but I want to allow others who don’t have design programs to modify the content areas and generate PDF files that can be saved or sent to other people.

The other people who may be adding the content, text and images, would need an interface where they could manage that content and generate monthly newsletters.

I have server space in a LAMP environment, so .NET applications won’t work. I’m also not a very advanced programmer, so hopefully the solution would be something I could figure out.

Any ideas about what I can do to set this up?