There is nothing inherently wrong with telling your dog “no,” except that it doesn’t give him enough information. Instead of telling your dog “no,” tell him what you want him to do. Dogs don’t generalize well, so if your dog jumps up on someone to say hello and you say no, he may jump higher or he may jump to the left side instead of the right. A better alternative would be to ask him to “sit.” Tell him what you want him to do in order to avoid confusion.
There is an ever-growing list of agility sanctioning organizations. The ones you’ll hear about most often in the US are NADAC, AKC, and the USDAA (see below for a more complete list of national and international groups). Each organization has its own rules and style. For example, NADAC courses are spread out and focus on speed. They often challenge the handler to send their dog through the course at a distance. USDAA courses are “tighter” and more technically challenging.
RutRoh is an English Sheep Dog, born Deaf.  He is a wonderful dog and family companion, however, being deaf and living in Dallas, his safety was one of the reason he was brought to us for training.   His owners didn't want to have restrict him to be on a leash all the time.  They wanted him to be able to run and play and have a way to communicate with him when he was not in view of them.
Certain breeds, such as Doberman Pinschers, German Shepherds, Border Collies, Labrador Retrievers and Golden Retrievers, have reputations as being easier to train than others, such as some hounds and sled dogs. Dogs that have been bred to perform one task to the exclusion of all others (such as the Bloodhound or Husky), or that have been bred to work independently from their handler (such as terriers), may be particularly challenging with obedience training.[2]
In recent years, a new form of Obedience competition, known as Rally Obedience, has become very popular. It was originally devised by Charles L. "Bud" Kramer from the obedience practice of "doodling" - doing a variety of interesting warmup and freestyle exercises. Rally Obedience is designed to be a "bridge", or intermediate step, between the CGC certification and traditional Obedience competition.
Clicker training, a common form of positive reinforcement, is a simple and effective dog training method. Although it is still fine to train your dog without clicker training, many people find it helpful. With clicker training, you can easily and effectively teach your dog all kinds of basic and advanced commands and tricks. It's fast and easy to learn how to clicker train your dog