Brushing is something that should be done for all dogs. Even hairless dogs such as the Chinese Crested, should be looked after because they have a small area of hair that grows on the head and the legs. For dogs that don't shed such as the poodle, brushing is a good thing to do for them it keeps their hair from matting.
If you have a dog with a huge coat like a Golden Retriever or Siberian Husky, it helps them shed alot of their winter coat and gets them ready for summer. With those type of dogs, it's good to stop a little before you're done. Shaving isn't a wise idea because the hair that grows on those types of dogs, although it's massive, acts as an insulator for them by keeping the heat out. When you shave a dog, it actually can get hotter, especially if it's an outdoor dog.
I would say the two most important benefits of brushing your dog is the fact that dander is greatly reduced and that it keeps shedding to a minimum. Some dogs are impatient when it comes to brushing. I've had the best luck by starting out by doing it for 3 minutes. Make it a great moment of bonding by petting your dog by sliding your hand along the area you brushed gently. Tell your dog that he's a good dog and reward him or her with a treat if they are good sports.
Most dogs love brushing. There are different kinds of brushes to use. Slicker brushes are great for dogs like Cocker Spaniels, Poodles and Bichon Frises. If you have a long haired dog such as an Afghan a pin brush with rounded metal bristles would be more effective.
Another post on grooming you may want to check out is Brushing your dog's teeth. Now I must walk the pooches before Gigi goes nuts. Have a great night and feel free to share your thoughts. :)