Found some useful (since this is for story background and not historical papers) material in early 20th c public domain books, too.
Wish I had all that research I once did for fun one summer about the rise of trade in 12th-14th c English wool...but it burned up when I had my fire...but still, this has been fun, and I have learned what I wanted to know, the organization of and typical sizes of a medieval open field village...including job titles and what they do (like hayward ).
I used to know so much of this stuff. Amazing how 20+ years of not using it dulls the memory. And back in those days, I was more focused on the big Italian merchant houses and the impact of the Edwards' Scottish wars on them.
And so now, I go and turn this data into stuff I need for The Woman Who Loved the North Wind. I have 4 types of communities to flesh out, one not much more than a rural village, where the guy in charge is not much more than a rich peasant, two petty kingdoms, sort of like independent dukedoms, where the high level nobles also have their own estates, one or two of which have to be fleshed out a bit, and a mercantile town.
No, I can't just invent. No, I have to go and find out stuff like typical numbers of households, how certain types of agricultural activity was done pre-industrially (I knew some of it, but I was shaky on some of it), and other interesting tidbits.
Only bits and pieces of this background knowledge will rise to surface in my story in detail (like, yeah, I'm not going to talk about gathering puffball mushroom powder for putting into tinderboxes, although that was a favored tinder), but I sort of need this feeling of solidity to keep writing. I pushed through my draft, knowing I'd be going back, because although I was really a junkie about Medieval social and economic history, it's been a long, long time, and my memories just don't have enough of the data that I use to weave the background of a story.
But I got two really useful books in (Lost Country Life by Dorothy Hartley looks like the most useful), and then found another 14 on google books, digitized, and ready to dl as pdf ebooks for free.
My inner researcher is happy. My inner writer has the data, and Pink can now pull me by the ear and continue that scene I got stuck on....