I've just edited my mother-in-law's memoirs for publication. In her diaries, she starts with her earliest memory (attendance at a wedding, wearing a new hat), and then sort of moves semi-chronologically through her life, except now and then the manuscript wanders into the fact that she's just bumped into so-and-so who was her friend at such-and-such-time etc etc.
What I did in the end was to just get everything down onto my word processor. Then I went through dividing it into sections, colour coding the text as I went. After that, I took one section at a time - family background, neighbourhood antics, the war, marriage etc etc, pulling it piece by piece into something coherent. That bit about her earliest memory found its way into a section about half way through which dealt with the story of the romance of the couple involved.
The pictures etc. were the very last thing to go in, when I'd decided what should illustrate what.
You could do worse than beg, borrow or buy a copy of this book:
http://www.amazon.co.uk/Write-Publish-Family-H istory-Successfully/dp/1872883591/sr=11-1/qid= 1166632853/ref=sr_11_1/026-9393085-6869214
which is about the best one I've found on the topic. I've also read some of the author's own history titles, which are very well-written and produced, so I know he knows what he's talking about.