If you're a historian focused on a subject, let's say the Roman Empire, and find a interesting book on a subject you know little of, like feudal Japan, what do you do to try and estimate the credibility of the book?
What are the steps you take to ensure the book your reading is not bunk if a simple "author x book y historically accurate?" google search doesn't work?
There are two important things you should do in addition to a basic google search.
Check the publisher. This is a big shortcut and doesn't always work, but if you see something like "X University Press" where X is some university, that is a big sign that the book is meant for an academic audience and is at the very well at least pretty well sourced. There are plenty of books published by academic presses that I don't agree with or have bad arguments, or just generally speaking aren't the best - but they are at least academically minded. This stands in contrast to "trade books", which are often not meant for an academic audience and might not have as detailed footnotes, sophisticated an argument etc. I need to bold this: This is not a fool proof method. There are great books that are published by trade presses. This is one thing you can do to at least try to gauge the intended audience and general academic intent.
Read book reviews. Academics rely heavily on book reviews to stay up to date on the literature in their field. You just can't read literally every book that comes out and book reviews help you identify the key new works (or avoid bad works). Sometimes these are behind paywalls (editorial note: Dear academic journals in the humanities, get with the program and make your contents available freely so people outside the academy can actually become engaged with our fields.), but you can find thousands of book reviews at H-Net, a scholarly organization that, among other things, publishes book reviews and makes them available freely on its Networks (subject-based communities). www.h-net.org/reviews
Personally, I start with a google search to see if the author has an established reputation. No harm in taking an easy first step. Next I look at their academic credentials; I think that part is pretty self explanatory but it's also worth looking at who they studied under, not just the school. Then I look at citations, both the quality of their own references as well as who is citing them. If an author's name isn't showing up in other academic work, that's a red flag generally. I also look at what else they've published. If they are all over the map on subjects, I might take it more as pop-history. Finally, I look at the work itself; does it pass a gut check of reliability? Is it well written?
Edit: forgot a big one: who's the publisher? Some are clearly more reliable than others.
@ OP /u/InZaintJohn
A couple things.
A) "feudal" Japan is increasingly being seen as a bit of a misnomer due to the implication of it being homogeneous to the feudal structure of Europe, which is wrong - see here which I talk about it a bit.
B) The AH book list is a good place to start. Generally, authors of second hand sources will have really long, comprehensive lists of sources they used - have a look around and see. You can also google it - use a query like
"author name" site:www.reddit.com/r/askhistorians
and see how other people view the specific author.
C) Google Scholar (scholar.google.com) is good. Also search it up on JSTOR, and 8 times out of 9 you'll find some review or critique of the author's work.
D) Ask here :) I, and other flairs, can specifically help you with Japanese sources, but anything else goes as well.