David Barnes @ Packt

If you're thinking about writing a tutorial book, before you start grab a piece of paper and make some notes around each of these themes.

They're in no particular order, and as you make a decision about one point it will affect the others too. There are no right answers to these questions -- the most important thing is to take a view, and be consistent.

1. Who is your perfect reader?
   Books are a private affair. Even if your book sells 1,000,000 copies, it will be read by one person at a time. Get a clear idea in your mind of who you are writing for -- just one person. Make sure it's somebody who you like and want to help. If the reader feels like you like them, they will like you.
   
2. Why will readers want to learn this?
   Every effort we make relates to some basic human want. Take a view on how your tutorial relates back to basic human wants and needs. People want money and security. They are curious. They want status. They want more free time. Try to understand WHY your reader will want to learn the topic covered in your tutorial.
   
3. Why do I want to write it?
   Be honest with yourself -- why do you want to write the tutorial? Capture that somewhere. And make sure your wants and the readers' wants are compatible, before you start.
4. Is the goal to "know" or to "have"?
   Some tutorials aim to lead the reader through a process, so that by the end they have the artiface they wanted to build -- the web site, blog, or wiki, for example. The reader's goal is to have something by the end. Other books, including most books about programming, aim to give the reader knowledge that they can use later. The goal is to know something by the end. You might build example programs, but you are unlikely to build the program you wanted as you work through the book. What will the reader have by the time they've worked through your book? A valuable object, or the knowledge required to build one?
   
5. What should the pages to look like?
   You can learn a lot about a book just by flicking through it. Will your book be mainly paragraphs of text? Or would you prefer if it had lots of diagrams, tables, screenshots, headings, bullet points, and so on. Which will be better for readers? Get a picture in your head before you start, so that you don't end up with a book that looks heavy with text, when you wanted something accessible and quick to read.
   
6. What's my teaching method?
   Figure out how you are going to deliver knowledge to the reader. What will your method be? Will you have one long example in the book? How will you decide what order to cover topics in? There are many possibilities, just make sure you've chosen one you like before you start? The best teaching methods have a balance of instruction, explanation, information and "connection" (the bits that show readers why they should care). Every few pages should contain a bit of each.
   
7. What's the high concept pitch?
   A high concept pitch means picking another successful book  or series and drawing an explicit comparison with it. "Jaws on a spaceship" is a famous high concept pitch for a movie. Yours might be "like a Rough Guide travel book, but about Drupal". Then make sure you have a copy of the "comparison" book, and 'borrow' as many of its good points as you can.
   
8. What selling points do I want to appear on the cover?
   Before you can appeal to readers, you need to appeal to customers. Customers decide to buy usually based on just a couple of hundred words that set out the selling points of the book. Try writing 200 words or so that explains to your reader what this book will do for them -- how it will give them what they want. Then when you write, make sure that above everything else you deliver on these promises.

Taking a view on each of these will make your life as a writer much easier and more enjoyable later on. Sharing these answers with your editor if you have one will also mean they can contribute far more to helping you write well.