If you are interested in showing your GS your dog’s breeder will normally be able to point you in the right direction. It’s very important when buying a puppy to let the breeder know that you are interested in showing as they will be able to help you select a puppy that at 8 weeks has no obvious faults for the show ring.
Ring Craft classes are a great place to start, the KC will have a list of training clubs in your area. You will find ring craft is normally a very social gathering of like minded people, some of whom will have been showing years and others that are very new to the game like you. It is an excellent place to socialise a young puppy and a great training ground for the show ring. A normal evening at ring craft will have you all standing you dogs and moving in small groups, you will also have a couple of turns of standing you dog for different people to go over and moving it individually, the trainer at this point will be giving you all of their attention and offering helpful advice and pointers to get the best out of your dog. Ring craft sometimes organise match nights, where they bring in an outside judge, this is normally held as a knockout competition where the dogs compete against each other in pairs until the unbeaten dog is awarded Best In Match.
The German Spitz is a free stood dog, this means they are trained to stand and look at you, normally because you have something tasty (a piece of cheese or liver) in your hand. They are stood square facing you with the tail and ears up. 
They are stood on a table to allow the judge to go over them. They are also normally measured in the ring. This is done on the table using a hoop type measure to check they are not oversize. Although sometimes in the case of a small Klein the 9 inch (minimum size) measure and in the case of the Mittel the Klein measure used to make sure they are not too small.
In your class when you enter the ring, the steward will check your number, you need to stand you dog in the line, normally a judge will ask all the class to move round the ring together. Then the first dog will be put on the table, gone over by the judge and moved individually, normally a triangle and straight up and down. This can vary from judge to judge so watching the class before yours is always a good idea and listen to what the judge asks, as sometimes they do change things from class to class. Once every dog has been seen, the judge will have another look at the dogs, at this point he may ask you all to move round together again, or watch one or two moving across the ring and back. He will then place the class first to fifth in order of merit.
The dogs are judged against the breed standard which is a description of how the dog should look, act and move, the dog that wins Best of Breed is the one who, in the judges opinion, comes closest to the standard.
Link to KC Klein Breed Standard
Link to KC Mittel Breed Standard
There are four types of show
Companion - open to everyone, enter on the day. KC registration is not required. These are normally held along side village fates to raise money for charity.
Limit – normally limited to club members
Open – open to all entries usually have to be sent in four weeks before the show.
Champ Show- only show with CC’s on offer. Some classes will qualify for Crufts . Entries usually close about two months before the show
Classes
MINOR PUPPY For dogs of six and not exceeding nine calendar months of age on the first day of the show.
PUPPY For dogs of six and not exceeding twelve calendar months of age on the first day of the Show.
JUNIOR For dogs of six and not exceeding eighteen calendar months of age on the first day of the Show.
YEARLING For dogs of twelve and not exceeding twenty-four calendar months of age on the first day of the Show.
BEGINNERS For owner, handler or exhibit not having won a first prize at a Championship or Open show.
MAIDEN For dogs which have not won a Challenge Certificate or First Prizes at an Open or Championship show (Minor Puppy, Special Minor Puppy, Puppy and Special Puppy classes excepted, whether restricted or not)
NOVICE For dogs which have not won a Challenge Certificate or three or more First Prizes at Open and Championship shows (Minor Puppy, Special Minor Puppy, Puppy and Special Puppy classes excepted, whether restricted or not.)
TYRO For dogs which have not won a Challenge Certificate or five or more First Prizes at Open and Championship shows (Minor Puppy, Special Minor Puppy, Puppy and Special Puppy classes excepted, whether restricted or not.)
DEBUTANT For dogs which have not won a Challenge Certificate or a First Prize at a Championship Show where Challenge Certificates were offered for the breed ( Minor Puppy, Special Minor Puppy, Puppy and Special Puppy classes excepted, whether restricted or not.)
UNDER GRADUATE For dogs which have not won a Challenge Certificate or three or more First Prizes at Championship Shows where Challenge Certificates were offered for the breed ( Minor Puppy, Special Minor Puppy, Puppy and Special Puppy classes excepted whether restricted or not)
GRADUATE For dogs which have not won a Challenge Certificate or four or more First Prizes at Championship Shows in graduate , Post Graduate, Minor Limit, Mid Limit, Limit and Open classes, whether restricted or not where Challenge Certificates were offered for the breed.
POST GRADUATE For dogs which have not won a Challenge Certificate or five or more First Prizes at Championship Shows in Post Graduate, Minor Limit, Mid Limit , Limit and Open classes, whether restricted or not where Challenge Certificates were offered for the breed.
MINOR LIMIT For dogs which have not won two Challenge Certificates or Three or more First Prizes in all at Championship Shows in Minor Limit, Mid Limit, Limit and Open classes, confined t the breed, whether restricted or not at Shows where Challenge Certificates were offered for the breed.
MID LIMIT For dogs which have not become show Champions under Kennel Club Regulations or under the rules of any governing body recognised by the Kennel Club or won five or more First Prizes in all at Championship Shows in Mid Limit, Limit or Open Classes confined to the breed, whether restricted or not, at shows where Challenge Certificates were offered for the breed.
LIMIT For dogs which have not become show Champions under the Kennel Club Regulations or under the rules of any governing body recognised by the Kennel Club or won 7 or more First Prizes in all at Championship Shows in Limit or Open classes confined to the breed, whether restricted or not at Shows where Challenge Certificates were offered for the breed.
OPEN For all dogs of the breeds for which the class is provided and eligible for entry at the Show.
VETERAN For dogs of not less than seven years of age on the first day of the Show.
Any Variety Not Separately Classified For breeds of dog for which no separate breed classes are scheduled.
Imported Register: Where an Interim Breed Standard has been approved by the Kennel Club.
Show Terminology
CC or Challenge Certificate – sometimes also called the ticket. This is awarded to the best dog and best bitch at a Championship Show, where CC’s are on offer for your breed. Three CC’s must be won under three different judges (one of which must be once the dog is 12 months old) for the dog to become a Champion.
Below are some books which will give much more in depth information on dog showing.
Showing Your Dog (Positive-Training) by Juliette Cunliffe
Good Showing: The New Exhibitor's Guide to... by Peggy Grayson
Show Me! by D.C. Cole
Absolute Beginner's Guide to Showing Your... by Cheryl Smith
