Fantasy usually requires less research than, say, historical fiction, but there are a few things fantasy authors need some knowledge of, like horses, how different weapons work, and a basic understanding of social structures, economics, and forms of government. But Daughter of the Wildings, being set in a world loosely inspired by the American West of the 1880 (and thereby dipping its toe ever so slightly into historical fiction), needed a little more research than that.
Take Silas and Lainie's guns, for starters. I know nothing about guns, so I did a lot of research into them, especially six-shooter revolvers of the sort that would have been used in that period. Not to the extent of naming specific makes and models, which of course wouldn't exist in a fantasy world, but enough to make what the characters do with their guns realistic enough that the gun enthusiasts among my readers (hopefully) won't laugh at me and then stop reading. My search history now shows a lot of Googling for sites that sell authentic replica guns and ammo, as well as Youtube searches for videos about shooting and quick-draw techniques. (My rule of thumb for writers: if your Google searches don't put you on a government watch list, you're doing it wrong :-D)
I also researched clothes of the period, mostly when I was working with my cover artist, Mominur Rahman, to develop Silas and Lainie's look in the cover art. Wild West Mercantile and Western Emporium are two great sites to look at for replicas of authentic western clothing of the period (and maybe buy yourself a little something, too!).
One thing I did a lot of research on was wages and the cost of things in the 1880s West. Money has to come from somewhere, and there has to be a rational basis for wages and prices, and this seems to be something that not a lot of fantasy authors pay much attention to. One of the most useful sites I looked at, that listed prices on items from canned goods to a new house in Deadwood, South Dakota, in the 1880s (based on newspaper ads of the time) is now, sadly, defunct. I was also able to dig up lots of information on other sites, too. This site, How Much Stuff Cost Long Ago, was really useful for calculating prices. So I did a lot of research and calculating and converting from dollars into the currency used in the series, and filled sheets and sheets of paper working out stuff like how much a meal would cost and how much a trail hand would earn on the cattle drive. Maybe it doesn't really make much difference, but I hope it gives a little more authentic feel to the world.
And then there's horses. Horse lovers, I've learned, are as particular about accuracy as gun buffs are. And I have the same amount of real-life experience with horses as I do with guns, which is to say, none at all. Fortunately, I have a number of online friends who know and love horses, who have also served as test readers on my books. They've given me a lot of information and corrected a lot of inaccuracies. And of course, there's always Uncle Google, for when I have questions like how far can a horse travel in a day (I already know a horse cannot gallop 90 miles in one day), and what's that horse color called? Do horses even come in that color? And how much does it cost to board a horse in a stable?
From Log of a Cowboy, I learned how cattle drives worked, what cowboys did on them and what daily life was like on the drive, how cattle behaved, and, best of all, what kinds of things could go wrong on a drive. I learned about river crossings and dealing with flooded rivers - and why most cowboys had a deep fear of drowning, the effects of bad weather on the cattle and the work, dealing with stampedes and rounding up the cattle after a stampede, tactics used by rustlers, and all sorts of other fun stuff. If you're interested in learning about that period of history, The Log of a Cowboy is available free online at Project Gutenberg and AmericanLiterature.com, and in various editions at Amazon. Keep in mind that it wasn't written for 21st-century sensibilities, so some readers might find some of the content offensive, even though it was perfectly acceptable for its time.
Some other helpful resources for Daughter of the Wildings research were the blog Wild West History, Legends of America, and Google Earth, which is great for researching physical settings.
Of course, Daughter of the Wildings isn't meant to be a factual account of life in the American West in the 1880s, and the heart of the story is not the research but Silas and Lainie's magical and emotional conflicts and journeys. But I hope that my research makes their world a more authentic, believable place and will help readers have a richer, more enjoyable experience.
Plus, I learned that cows can swim :-D