Think about when you first joined your team. What applications did you need installed? What systems did you need an account on? What did you need a demo of, and what institutional knowledge was critical to you coming up to speed in those early weeks? When you onboard someone new, they're going to have these exact same questions. Create a shared, collaborative space where this information can persist and be updated over time. New hires will find this onboarding guide invaluable, and in the course of onboarding, they can update it with anything they think others would appreciate, too.