Nourish is sort of the go-to spell for druids at the moment. It's the lowest mana cost per healing, and it refreshes Lifebloom to boot! Regrowth should only be used in absolute emergencies. Healing Touch is good if you need to get someone up from heavy damage.
My biggest problem with this guide is that it's Regrowth heavy and Nourish light, but after that, it doesn't really include a lot of other important techniques, like ways to avoid overhealing. If you're rejuving dps every time they take damage, you're going to run low on mana quickly. You want to make sure that Rejuv is just enough to bring the dps to full, otherwise you're wasting mana on overhealing.
Kathy, I said, "I'm lost" though I knew she was sleeping
I'm empty and aching and I don't know why
Counting the cars on the New Jersey Turnpike
They've all gone to look for America