Oh, sadness. I just read that William Zinsser died on May 15, 2015. Among other things, he was the author of my favorite nonfiction how-to, On Writing Well: An Informal Guide to Writing Nonfiction.
Zinsser begins by emphasizing that nonfiction is a personal transaction. It isn’t removed from the writer; it flows from who the writer is. A passionate, enthusiastic writer will bring passion to the topic. This emotion will draw in readers that might normally never be interested in bubble gum or a forensic study of George Washington (these examples are mine and are from children’s nonfiction).
He talks about the importance of making your work simple and accessible. In part, the author does this by avoiding needless jargon. Yes, you might need to use a thesaurus because finding the right word is important, but you don’t have to poor in all the specialized terms that would simply obscure the meaning from your readers.
If you’ve never read this, I highly recommend it. This and Yolen’s Take Joy are my two favorite books on writing. I skim and reread them periodically which, if you’ll excuse me, is what I’m about to go do.