I'm fairly certain all you have to do is complete the Elona Reach mission, (by clicking the "enter mission" button while in Elona Reach). After that, the game should dump you back in augury rock. You'll then have to travel to the next two desert missions, dunes of despair and thirsty river, unless you've already completed them.
I think everything is pretty straightforward after that. There are primary quests associated with traveling to new mission outposts, but it's been so long since I've taken a new character through a campaign that I can't remember any of the primary quests. But yeah, following primary quests should get you where you need to go.