While there are certainly a lot of duties and responsibilities for an effective sales director, my experience in direct response has taught me that above all else, a quality sales director needs to be sales oriented.
So many organizations take it for granted that because someone has a certain background they can sell something, and also teach others to do the same. This is simply NOT true.
There are a lot of well-intentioned sales directors out there that honestly couldn't sell an oar to a drowning man/woman.
I say put everything else aside, and look for the following three primary assets in a sales director:
1. Must be able to sell things.
2. Must be able to train/inspire the people around them to do the same.
3. Must lead by example in all aspects of their professional life.
Honestly, there isn't much beyond those items that really matters, and but for the special elements of the quality directors I learned from - they're almost all a dime a dozen.