Any suggestions on dualing an elven mage?
This really depends on what you like to play. For questing, Druid is very good. Later you may wish to add a 3rd class for a bit better dps, Warrior is good, Scout is also good.
I myself have a Mage/Druid, not the best endgame mage but I manage to do ok. I keep putting off getting a 3rd class but if I do get around to it, it will be Warrior.