It seems like every time I visit the War Table, there's another new area unlocked. It always asks me if I want to gather my party and go but usually I decline because I'm still working on another area. And by the time I finish that area, I have 5 or 6 more open and ready for exploration. How do I know which one I should go to next? There doesn't seem to be any indication of order on the location itself (level rec, etc). Is there a certain order to visiting these locations or is it just a free-for-all of exploration goodness?
The location with the glowing green rift over it is the next story mission.
If there is more than one glowing green rift, you'll have to pick one and the other will go away, but the game will warn you about that.
The rest of the locations are more or less just open world exploration to get the resources needed for the story missions and so they can be done in any order. In fact they should all be done bits at a time as they have a wide variety of difficulty within them.