collecting information and wondering how to start

For quite a number of years I've had this idea for a story (novel?) that I have been collecting information for. I have folders and pictures and notes, but no idea how to get this started. So, I'm thinking I'll just start in the middle and work my way out to the edge....I'm thinking this will be the writing equivalant of dropping a pebble in a pond -- you never know how wide the ripples will spread!

So, today's assignment for myself: Description of a character for the story, so here it is:

Character Description – “Tildi”

She was tall for a woman of her time, nearly 5’5”, and thin for a woman with four children. When she was young, she might have been called willowy, now she was just a thin woman with lines around her eyes from working in the sun.

Perhaps her strongest feature was her hair. Long, of course, for no Christian lady would cut her hair off except in severe illness, it was thick, heavy and a deep auburn color. Now there were a few strands of silver among the dark as well. She wore it parted in the center, pulled into a snug braid that was then pinned into a knot at the base of her neck.

Her eyes were light, not blue or gray or green or brown, but a mixture of blue and green with golden brown flecks. When she was angry or had been crying they appeared very green.

After years of working to keep a home, her hands were still slim with long fingers, but they were strong and had the callous of splitting firewood, tending a garden and wringing out laundered clothing.

As a woman on the plains of Arkansas in 1860, she was a rarity of another sort, she could read and write. Her mother had seen to it that she and all her brothers and sisters had learned to read early on, and now she was teaching her own children out of the Bible her father had given she and her husband as a wedding gift. That Bible was her family’s record book as well, where each birth and death and marriage was carefully recorded.