Spoiler Alert: What's the best way to let them know there's no Santa?

My kids are 7 years-old, and young for their age. I’d like to make this revealing a sort of “rite of passage” with a positive feel to it. Do you think it’s too early to let them know? I’d like it if they didn’t hear it from friends/kids at school. Suggestions, experiences, your if-I-had-to-do-it-over-agains appreciated!