Start going to as many shows as possible, make friends, and ask lots of questions.  When it comes time to get a pup, expect to spend big bucks on a show prospect, and as a first timer, expect the possiblity of co-owning, and also expect to possibly be turned down on the good show prospects.  They will likely go to experienced homes.  So, your best bet if it's something you're serious about is to start getting out there, get as familiar as possible, and make friends with the breeders/handlers/judges, whoever you can.  You'll have to show that you are serious, and have the desire to actually do it.  Good breeders are not going to just give some random person one of their show quality dogs.  (I'm not saying you're just some random person, but the show prospects typically go to homes with show experience, and a proven record.  Breeders want their dogs to win, and they want them to go to a home that is serious about showing). 

I would also look into the financial and time burdens that come along with showing.  It's by no means a cheap hobby.  You will have travel costs, handler costs, (or if you want to do it yourself, probably some classes) and all sorts of things that come up.  I'm sure someone can chime in with the average cost of finishing a dog, I'm sure it's many of thousands when all is added up.

It takes a quality dog, a talented handler (yourself or a professional), time, money, travel, perserverence, classes, and as you've already noted, a mentor is helpful. 

We have just started showing Cleo, four shows and she has been placed in all of them and the last one she was placed 1st in the minor puppy class - 6-9 months.   

We are lucky that we have a very good ring craft class near where we stay and the 'judge' is an actual show judge and his knowledge, help and encouragement has been great.  The class is really good for Cleo's socialisation too - although I think she thinks its her playgroup as it takes her about 30 minutes to calm down enough to behave, she just wants to play with her friends.  Many different breed go along - Newfoundlands, huskies, akitas, labradors, whippets, eurasures, french bulldogs and, of course, one special doberman!!

As to the cost of showing, that I think depends on how serious you are and how far you are willing to travel.  We only show in Scotland as we are not be allowed to show Cleo south of the border as she has a docked tail and that is banned in England and Wales but that is fine as it is purely a hobby with us.  We tend to take the caravan and stay over for a couple of days so get a mini holiday too.

We have certainly picked up loads from going to the championship shows and watching the prize winning dogs and how their handlers work them.   Most people, although competitive, are very friendly and are keen to give advice and encouragement.

It might be different in the US but this is our experience in the UK - so fa so good.

You can't just register dogs out of the blue.  To AKC register a dog, both of their parents must be AKC registered and the breeder of the litter must have registered the litter and provided you with the individual application, or the dog must be registered with another AKC recognized club.  For instance, I can (and have) registered my Canadian Kennel Club registered dogs with the AKC for showing purposes.