Early exposure to grooming is paramount on creating a positive connection for your dog. This needs to be created at home as well as at the grooming salon.
I always recommend the earlier the better for puppy grooms to start. It is important for the health of your puppy that they receive two series of shots before any exposure to other dogs or facilities that see a lot of dogs. This is usually done by 1012 weeks. As soon as you have your puppy, especially if you have to wait a bit before seeing the groomer, start with short and fun sessions with brushing. Lots of praise and treats will help them to associate the brush with positive things. Be sure to also get your pup accustomed to being handled; pick up their feet and tail, hold their faces and ears and let them get comfortable to being picked up and moved around. This will all help when it comes time for them to be groomed.
The first trip to the groomer should involve very little actual grooming. You want the puppy to associate the groomer with a positive experience. Typically on their first few visits puppies get a bath and nail trim with minimal trimming; usually the feet, eyes and potty areas. Try to find a grooming shop that will keep your puppy for a few hours to allow them time to acclimate to the sights and sounds of the shop. A added bonus would be a shop that offers a bit of puppy play time to socialize with other pets. This way they don't get rushed or forced into anything. Sometimes puppies will do great and have no problem with the process, others will act like the world is ending! The amount of exposure they have to new environments and experiences before ever leaving their litter mates has a huge effect on how they will adapt in their new home. Don't worry if you have one of the less cooperative puppies, it just means they need a little more consistency and time.
Puppies should visit the groomer every 24 weeks when they are young. This allows them to get comfortable with the whole process before every needing to get a full cut. Many owners make the mistake of waiting until their puppy is in need of a cut or very tangled before bringing them in. This forces the groomer to push the puppy out of their comfort zone and can be a very negative experience for all involved.
In between trips to the salon, you can continue to work with your puppy. One thing to keep in mind is that puppies frequently react to things with fear if they don't understand them. It is important to take things very slow with them so they can relax and understand that nothing terrifying is happening. If you are not comfortable with your puppy crying about things, as they often do, it is important to not try much at home. If you stop brushing because they throw a fit, this will reinforce this behavior and associate the brush with negativity. It is always best to go in to see a professional to be sure you are using the proper equipment in the right manner so you don't accidentally hurt your puppy. Many people come in and say they don't brush their dog because it hurts them. This is almost always because they are using the wrong type of brush in the wrong ways.
If you stick with a consistent schedule and keep things positive you will have a puppy that looks forward to their trips to the groomer. This makes for a much more positive and relaxed experience for both you and your pup.