Look at your dog, what breed group is it from? If the dog is from the sporting group do you go hunting with your dog? If the dog is from the herding group do you have livestock? In all honesty, probably not. Most people will pick a dog breed more on the way it looks and not what is was bred to do. That simple fact will get people in more trouble with their dogs than not.
If you love to garden then you don't want a terrier breed since they are noted for digging in pursuit of their prey. If you don't like to go out and be highly active then stay away from most working dog breeds as they are known for high energy.
But what if you do have a dog that you picked for their breed attributes? Where do you get help on how to start working with your dog for hunting or herding. Of course the best place to start is with a good book on the subject, like the book below: Working Retrievers
Yes you can find lots of information on the internet too but much of it can be incomplete or flawed. Another place to look will be the local dog clubs that are devoted to the same breed as yours. They will have information on competitions, Sales of training equipment and most of all other people that are doing the same thing as you are with their dogs.