First make sure you know what's already there – nobody's waiting for three MS-SQL-to-Firebird conversion guides.

Then ask yourself what's missing, and what may be useful for Firebird users in general, or perhaps just for a specific group.

Also ask yourself what you would like to write about. The most logical choice would be a topic you are familiar with, but you can also pick a subject you'd have to learn more about first (this is much more work of course, but a great learning experience if you're willing to invest the time).

You don't necessarily have to write an entire book, guide or article. Maybe there are already people working on a larger production, which you can contribute to. Maybe you can write one or more chapters for a book. Or maybe you can supply raw documentation material for a subject you know a lot about.

Talk about your ideas – or your search for ideas – on the firebird-docs list. The posting frequency can be very low at times, but rest assured that if you post there, your message will be read, and replied to.