Proper grooming is mandatory if you want to maintain the health of your dog. Regular grooming sessions will ensure that your dog will not only look but feel its best. You should start a habit of grooming your dog while it's still a puppy so he will be accustomed to it rather than have trouble getting used to it as an adult.
Brushing your dog at least once a week is effective for removing all the loose hair that builds up. This also prevents the hair from getting matted up because dogs shed all the time. Grooming brushes for dogs are relatively cheap and durable so you will most likely only need to purchase 1 during your dog's life. The best time to brush your dog is right before bathing. However, brushing should be done more often than bathing, so you can choose the other brushing times at your discretion.Have a look at http://mrgroom.com/ for more info on this.
Bathing should be done once a month for dogs with short to average length hair. Dogs with longer hair should be bathed about every 2-3 weeks. When bathing, make sure all of its hair is lathered up well. Most importantly, make sure to keep water out of your dog's ears as this can lead to ear infections.
Nail trimming should also be done regularly; how often you trim depends on the type of dog. You can usually tell when it's time to trim by feeling how sharp their nails are. When you trim nails, you only want to trim the very tips; never cut down too far as this can be painful for your dog. In general, you want to keep the nails trimmed just enough so they don't touch the floor when walking.