If you are going to write about bananas, for example, read books about bananas, talk to people who've been in Bananaland, even buy tickets if you can afford it, zip on a huge banana skin before you write a fantasy novel with Arnold the Banana flaying the forces of Hungry Darkness, or at least before you revise it. Because if you take a white character and dress them in banana skin, then someone named Denise the Banana will call you out for it.
Which is all right if you're a white author trying to overcome your prejudice, but how about if you're non-white? Because I'm Indian, but I know little to nothing about Indian culture. As a kid I created an alter-ego Jenny Andrews who was Indian, but completely Americanized and a secret agent to boot. The most I know is Hindu mythology because we have a lot of books, and I do plan to write a book combining Hindu mythology and superheroes, but I know nothing about transportation or politics there.
And if you're Americanized, you're most likely going to write about white people because you mainly see them in the media and in school, and in your circle of friends. Even if you join the Banana Students Association, you may not feel comfortable writing about bananas because you know little beyond their sweet taste, especially when fried in butter. You might write about being an Americanized Indian, but you might also want to tackle with righteous fury the bananas who have been trampled on when everyone preferred apples.
The best way to do research on unfamiliar cultures is to read literature on that culture. The textbooks provide guidelines, but go with fiction, with essays, maybe even with artwork. One book I read for my manuscript was about Chinese restaurants, filled with surprising information I could integrate into the book. Use your libraries, both school and public, and read read READ. And it you want to tackle modern racism, go with this book:
This book provides a snapshot of 1960s racism from a white man who tinted his skin, shaved his head, and dyed his hair to appear black. Then he traveled in the Deep South to find the truth of racism. A disturbing fascinating, and heartbreaking study that will definitely put you into someone else's shoes. Along with a whopping dose of common sense.
Banana skins indeed. What will they think of next?