I created a program that generates static web pages to navigate round a directory full of photographs. From my experience I would say:

1. Develop it in Perl (of course)
2. Have the script interpret a simpler language that "real people" can use (my current best thought is something BASIC like)
3. Have different "levels" of customisation for different needs and different levels of your users
4. Write "How to customise your web page" documentation before you write your code (it will be wrong but the exercise of writing it will help clarify how it should work)

I would also suggest that you steal ideas from my software but I haven't got round to releasing it yet.

Update: I have now, it is here