First, I suggest that you write your memories as they come to you, not in a linear manner and not neatly in organized chapters, just a few paragraphs at a time. Remember, a complete book is a collection of words that make up paragraphs. Those paragraphs make up chapters that will make up a whole volume. The idea is to write as much material as you can. Put those stories away in a folder, and once you have a large number of written sheets of paper, read through them. The chapters will reveal themselves, and the structure of your book will become very clear.