You are almost ready to start writing your non-fiction book. Once you have finished your outline by dividing each topic into sub-topics and sub, subs... and sub, sub subs...etc., you'll need to complete the research for each of them. Don't forget to keep track of three things as you proceed with the remainder of your research. They are:
1. Keep track of the people who help you research the topic for your non-fiction book. You'll want to mention them in the Acknowledgements section of your book.
2. Write down pertinent information about the references you use, including the pages numbers for specific quotes.
3. Keep track of topics to be included in the index.
You'll be glad you paid some attention to these things. It's so much harder at the end of writing your book if you have to go back and try to determine where you found your information. And, don't ever underetimate the importance of keeping a good record of the people you'll mention in the Acknowledgements list. Woe be it if you forget someone.
Okay, so your research is completed or nearly completed - there's always a bit more to do once you start writing. Now, it's time for me to say, "Ready, set, go....."
The way you write your book is up to you. You can either write it from start to finish or you can write a topic at a time. Within your outline, you can skip around from topic to topic as the mood strikes you. Just remember to go back through it carefully to smooth out and blend together the topics and chapters.