While you’re at it, you should definitely join Meteor Club. The private Slack chat is an invaluable resource if you’re serious about Meteor development. Plus, I’m almost always hanging out there!
Allow & Deny Challenge - Check Yourself – Can you write an air-tight set of allow & deny rules? Take a look at Sacha Greif's challange, try it for yourself, and take a look at my solution.
Black Box Meteor - Shared Validators – Validator functions for Meteor collections belong on the server. Find out why from a hands-on perspective.