I've done a lot of Googling and found interesting links, like this, this, and this, but would like more scholarly sources, especially where people are disagreeing (on effectiveness, manufacture, amount of training).
(1) Care and feeding of the longbow itself. Google has produced the basics: the bow needs to be waxed/oiled regularly; the string replaced fairly often; the bow needs to be kept unstrung when not in use; you need to keep all of it--bow, string, arrows--dry, or they'll warp and become ineffective. But how dry is dry? Will a run of damp weather spoil a bow/string/arrows in their cases? How hard are these things to make, and how expensive are the materials? I've been getting a lot of varied noise on that last one.
(2) What it was like to be a yeoman. I keep tripping across references to the Mary Rose and "skeletal deformities"--shorter upper arm, longer lower arm, massive shoulder/back muscles. The lack of a visual is making me twitchy; just how abnormal was a yeoman, physically? Could you pick one out of a crowd with a shirt on? With bulky coat or cloak on? Did they move differently? Would it ruin someone for hand-to-hand/shortsword/other melee combat? The draw weights of longbows are impressive and it's gotta build massive upper-body strength, but then again, they've been trained to pull their arms back, not strike forward. I keep seeing seven years cited as the starting age, and about ten years to complete the training--that right?
(3) What it's like to use a traditional medieval bow. (AKA: Any SCA people here?) What does the wood (ash, yew, elm?) smell like? The oil/wax? What does it feel like to draw a bow? What muscles will ache if you overdo it? Oh, yeah, and when they say five to six feet: is that strung, or unstrung?
pikemen, cavalry, and general medieval war tech
Gotta admit, I haven't Googled this as much--been spending most of my time on syphilis and the longbow. I've got the basics and will probably turn up more, but good links would be appreciated. Points of interest: Cavalry before and after the introduction of the stirrup (around the time of its advent in particular); pike/spear use in general; the usefulness of chariots. Sieges. Castles. How all these weapons and techniques worked together, or against each other. Y'know, all the fun gory stuff. And I wouldn't turn down any good info on medieval farming or anything, either.
syphilis - tertiary and congenital
This is freaking killing me. I've got a general description of all the symptoms--the physical stuff is easy--but can't find more details on the dementia caused by tertiary syphilis, or the mental effects of congenital syphilis. The history of Henry VIII is fascinating, but I want something more specific on the actual disease. "Insanity" isn't that specific. (It's a fantasy world and I can fudge, but I want to know what I'm fudging on first.)