Does anyone have a best intro to chess book? I've played my entire life, but have never formally studied the game. (I'm looking to slowly develop a framework so I can teach my kids more formally.)

For you I would start with the Play Winning Chess series by Yasser Seirawan. After that take a look at the Silman books. I actually prefer  "The Amateur's Mind" but his "Reassess Your Chess" is actually much more comprehensive.

I write code and sometimes stories. jakeacasey.com

Finally, I would recco picking up Logical Chess: Move by move, by Chernev. This book takes master games and explains the principle behind literally every move, which is important for developing an understanding of *why* people are making the moves they are. What are they thinking about? What does the move do?

Not finally, there are tons and tons of resources for kids, because kids are actually the best players, lol. Chesskid, branch by branch by Pruess. Play a lot of slow-ish games, and analyze all of them without an engine first, and then an engine afterwards.