Adequate exercise is extremely important. This will make life with your dog much more enjoyable. If your dog is tired, he will be less likely to look for negative ways to fill his boredom such as chewing your coffee table.
Since you will be out and about with your dog in order to fulfill his exercise needs, make sure to have a securely fit collar (you should be able to get two fingers underneath the collar, but not any more) with an ID tag, a rabies tag, a dog license (available through your local municipality) and a parks license if you plan on visiting dog parks with your pooch.
You will be responsible for helping your dog direct his energy positively. Exercise can be leashed walks, dog parks, play sessions with neighbor dogs, running with you, playing inside or outside, etc. Exercise requirements will depend on the breed and age.
Age
Puppies under 5 months generally need several (4-6) shorter walks and/or play sessions. Normally they have spurts of energy and then a few minutes later may be ready for a nap.
Adolescents and young adults generally need more prolonged exercise periods. Normally they need between one and three hours of exercise a day. One of these times should be an off-leash romp in a dog park or a play session with friends. This burns tons of energy and is great for socialization.
Adult dogs between 3 and 8 years old still need a good amount of exercise, but less than an adolescent dog. One longer walk per day (between 45 minutes and an hour) plus bathroom breaks may be just right.
Senior dogs may be content with bathroom breaks, one leashed walk around the block, and lots of petting as a daily exercise regime.
Breed
By knowing the breed or mix of breeds your dog is, you may get a better picture of the amount of exercise your dog may need. Generally, herding breeds like German Shepherds, Australian Cattle Dogs, and Border Collies have high exercise needs...they were bred to move! On the other end of the spectrum are toy breeds, such as Papillions and Bichon Frises, which were specifically bred to be companions and may have less energy. Ask your veterinarian or other animal professional about the exercise needs of the dog you are adopting.
These are only general guidelines. Determine your dog's exercise needs and make sure they are met every day.
A dog's paradise...a fenced-in yard
If you already have a fenced-in yard, make sure the first few times your new dogs play in the yard, you are there to supervise. If your fence is less than 6 feet high, be aware that your dog could jump over the fence. You may want to use a long lead at first. Watch your dog's reaction as different distractions go by (kids, dogs, and squirrels). If your dog tries to jump the fence, you may need to always supervise your dog when she is in the yard, or seek advice from a professional trainer or animal behaviorist.
If you are thinking about fencing in your yard, keep in mind the height and material of the fence. Different types of fencing include chain link, wooden privacy, and invisible fencing. Also, take into consideration the base of the fence. Could your dog easily get under the fence?
The pros and cons of invisible fencing
Invisible fencing is generally less expensive than a physical fence and allowed by neighborhoods that may not allow other types of fencing. Unfortunately, invisible fencing does not keep other animals or kids out of your yard. Some dogs will even take a shock just to chase something really enticing such as a squirrel. Sensitive dogs may also shut down or redirect stress caused by the shock or the mere thought of a shock...positive training methods rather than the use of aversives such as shock collars are always preferred.
What about other methods of confinement outside?
You may consider using a cable system to confine your dog to your yard. Only use this method if you are supervising your dog. Dogs that are unsupervised may pull the stake out of the ground, get tangled in the cable, hang themselves, or be stolen. They may also be teased by kids and other dogs that are passing by, resulting in a potentially fearful or aggressive dog.
Another popular cable system is one that looks like a clothing line. You attach the two ends of the cable to a tree and your house and then attach a second cable to your dog's leash. This allows for more freedom for your dog, but it is not recommended to be used for extended periods of time and certainly not without supervision.
Never leave your dog outside unattended
Keep your dog's outside behavior appropriate by playing with and watching your dog, instead of finding that your newly planted flower garden has turned into a construction site. Worse yet, s/he could go missing or be stolen without your knowledge or be injured with nobody around to assist!
Is your dog pulling your arm off when you walk her?
If your dog loves to pull you down the sidewalk or you need added control when your dog sees squirrels or other dogs, consider getting your dog a head harness or front-clip harness. These give you greater control by steering the dog's body, not just bracing against their pull. In fact, resistance against a flat buckle collar or regular back-clip harness makes dogs pull harder! If you get one, make sure to give your dog great treats when you put it on and only leave it on for a second or two in the beginning. Then, gradually increase the time until you can use it on a walk.