What's the best way to paint a ceiling?

Yep, I’m getting my house re-roofed; we had a bad storm, leaked, and now I’ve got discoloration on the ceiling in 4 separate rooms. That’s a lot of ceiling painting! What works best on popcorn ceiling (yes, I’d love to resurface and get rid of the popcorn, but that’s wayyyy too big a project right now), roller or sprayer? Any hints for taping off and other prep work?