Just run around checking every area, do every quest you have not done. After one of them - somewhere - someone will tell you to head to Deshaan. I have just got there on my level 16 Orc Rosiebelle. However I did all of Stonefalls totally in the wrong order and just ran around dealing with anything that didn't kill me so I don't know what the last quest should be if you do them in the right order.