1. How old does your dog have to be to start herding?
I don't know the answer to this question because my dog was already 5 by the time we took her herding instinct test. I'm not sure there is a minimum age.
2. What are the first steps that an owner should take to get their dog started in the sport?
You should find, preferably locally, someone to do a herding instinct test. The tests are often offered at herding events, but you can also find individual herding trainers that will test your dog. The idea is to see whether the dog is interested in and has natural ability to herd.
3. Any recommended sites, books, or articles that I should read (besides the ones on here - will read through this section soon)?
4. What are some characteristics in your dog that will hint at him/her being a good "herder"?
I'm sure those who are more involved in training can answer this question better than I.
5. Are there clubs? Associations? or is this an individual sport?
This site has a listing of herding clubs and groups - http://www.herdingontheweb.com/programs.htm
6. How do you find a trainer for this? I have been looking but unable to find one on the internet so far - will ask at the Schutzhund club next week as well.
A good place to start would be herding organizations, to see if there are any trainers local to you. Herding events in your general area might also help you find a trainer. I found both places I trained with Abby through Google.
7. What are the commands that are used?
When you first get started, your dog should have a pretty solid sit and down command so you can "drop" them and get them to stop running after the sheep. A lot of what we did was directing the dog using a stick, for going left and right, and the verbal commands for sit/down/stay. But we never ended up trialing, so I'm not sure whether it would be any different for people doing it on a higher level than we did.
8. What type of training does the owner/handler need?
You learn to direct your dog during lessons.