I would sign them all up for YNAB if you need to measure results. I just think it would be a lot easier to get someone to sign up for an account than it would be to make sure they got around to reading the book before the 6 months is up.

Also educational videos for a "lunch and learn" events because getting people together with free sandwiches to watch a video about financial literacy is going to be a lot easier to measure than figuring out whether or not people read the books you bought them.

You could also buy prizes for drawings for 30 day challenges, like people who track their expenses for 30 days in a row.

I just wouldn't give them books and expect to have something measurable at the end of 6 months. I just know how people are, they're busy, they won't get around two homework assignments.