Simple reasons you should have them in the first place
Work Happy: What Great Bosses Know
Managing Humans: Biting and Humorous Tales of a Software Engineering Manager
My first piece of advice to all new managers is "Schedule one-on-ones, keep them on the same day and time, and never cancel them."
Managers who don't have a plan to regularly talk to everyone on their team are deluded.
One-one-ones are where you learn about your team and what they are doing
Don't go more often than weekly
Don't EVER skip one-on-ones
If you can't meet at your designated time, reschedule, don't just say you'll do it "next time"
Don't assume that just because you don't have stuff to talk about, your employee doesn't need to meet