What level do I need to be/should I be in order to start and complete the Dragonborn DLC? Which character type out of mage, warrior, or thief is this DLC most orientated towards? I am thinking of picking it up soon and playing it with my Nemesis...

http://www.gamesas.com/topic/1439230-the-nemesis-build/page__fromsearch__1

It has choices for everyone.You can start it as soon as the Greybeards summon you.But you can visit Solstheim anytime.I recommend minumum level 20-25.