The grove for druids, Moonglade, is in the northern most part of Kalimdor, near Felwood and Winterspring.

It is west of the place where you are when you teleport to moonglade, behind the hill

Moonglade is a zone that is at the very top of the Kalimdor continent. If you are a druid, there is a teleportation spell that you learn to take yourself there and a druid only flight path that will take you to TB ( horde) or Darnassus(alliance). other people need to walk/ride there. Once there, you can take a regular flight path.

The druids of Moonglade were very excited to see me as i had just gotten to a level where i could finally take on bear form.

In the northwest part of Moonglade (I think he was in a cave)

Don't forget to speak to Dendrite Starblaze in Nighthaven when your done

Going to add a map link :)