Organize your thoughts and materials and consider how to make them available to your readers. You might publish a detailed journal as you first recorded it, or you can use your journal as an outline for an account of the events that are important to the story you want to tell. Outlining will be even more useful if you don't have many documents from which to work. You're never stuck with your first outline; you can add more material later if you think of it. Do remember, though, that no matter how interesting your life is, not every event will be suitable or interesting to the audience you expect will read your final product.
First person---"I," "me" and "we"---is used most often in memoirs and tends to make the story more personal. That isn't to say you can never write in third person ("he," "she" and "they"), especially when reflecting on an event that influenced the time you're covering at that point in the memoir ("I can hardly recognize the person I was then"). Memoirs are also most often written in past tense, but you might use present tense when interpreting your memories.
Write an opening chapter that focuses on the story you want to tell, and especially if you plan to publish the memoir, even if only to your loved ones, how you feel others might benefit from what you have to tell. Like a novel, your story should draw readers in. Describe a problem you've faced and overcome: "I've spent the better part of my life battling addiction to drugs and have paid the price in distance from my family and shattered health." Or start with the moment that changed your life for the better: "When I looked into that little face, so completely dependent on me, my heart nearly burst with love."
Tell your story in the clearest manner possible. That may mean starting with your birth or childhood. It may also mean reflecting back from a crucial moment to the earlier events that brought it about.
Be selective. This is most important if you intend to publish your memoir, and less so if the memories are for your personal enjoyment or sharing with your family. Your descendants may find fascination in details that would bore readers who don't know you.
Determine what format is required for your manuscript by any publisher you hope to interest in it. "Writer's Marketplace" publishes books and databases in which publishers have identified the material they want to publish, the forms in which they want to receive it, and the personnel to whom it should be sent. You can also self-publish through a number of electronic and "print-on-demand" methods. Amazon allows you to publish and sell your work for the Kindle e-reader through their Digital Text Platform and also has a print-on-demand service that will allow you to get involved in every step of the publishing process.
Select a printer, whether a local commercial establishment or an online service, according to how many copies you want and for what purposes. You can discuss formats and binding from classic manuscript forms and binders to professional-looking softcover and hardcover books with custom-designed covers. Don't be afraid to ask questions about costs and other obligations. Illustrations are another important factor to consider in the budget for your book.
Save your manuscript in one file or in chapters, using PDF, text, Word, rich text or whatever format your selected printer uses. Many of them handle a variety of file formats. PDF is popular because it crosses computing platforms and allows you complete formatting control. If you don't want to bother with format, however, your printer will prefer to receive a text file of some kind that can be manipulated for attractive publication. Upload your file to an online service, or download it to a flash drive or CD if you're using a local printer and your files are too large to email.