First, some biased suggestions for presents:
My and my wife's book on medieval and renaissance cooking—more than three hundred recipes, each with the original and how we do it, plus a variety of related articles. Just the thing for the cook in your life—or the medievalist.
This is the bigger book that the previous one is the cooking section of. Recipes, articles on how to make a pavilion, portable period furniture, a Germanic lyre, lots of other things, along with a good deal of my poetry and essays on historical recreation and related matters. Good if any of your friends are into historical recreation from the Middle Ages and/or Renaissance, especially through the Society for Creative Anachronism, a long term hobby of ours.
My most recent nonfiction book, good for futurologists, science fiction readers, and the proverbial intelligent layman. For whom my
are also possibilities.
But the one I really want you to read, because I want more comments on it, is my second novel, Salamander. Extra credit for physics and math types if you can figure out what my version of magic is modeled on.
For my unbiased recommendations, here are some of my past Christmas books—each the book that, for one year's Christmas, went to anybody I couldn't think of anything else for because I thought it was neat.
Talleyrand by Duff Cooper. Mostly for the fascinating subject, but it doesn't hurt that the author was the one member of Neville Chamberlain's cabinet who resigned over Munich.
and the book that just occurred to me for this year's Christmas book, some of our presents being given a few days late ...
And, for a final recommendation, His Majesty's Dragon by Naomi Novik, and sequels—a series I am currently rereading.