The first thing I would do is find a local AKC sanctioned dog show and just wander around and see what breed appeals to you.
Different breeds are shown throughout the day, so you might want to check the schedule and see what time breeds you are interested in show.
Then ask questions of the breeders there. But quick hint - do not ask while they are waiting to go in the ring. Always wait until they are done showing. Most handlers and breeders will be willing to talk to you, but some are snippy. A dog show is a lot like the DIS. Most are willing to help, but some are cranky with newbies. Don't let it bother you. Just move on to another breeder.
You can find out about local shows by contacting a local all breed club. You can start by looking on the AKC site. Click on the Events Tab on the home page. Then click on "Events and Awards". Click on your state to find things that might interest you.
If you are interested in finding a good breeder, and that is the best way to find out about the breed, you can also use the
www.akc.org site. Click on breeds, click on King Charles Cavalier Spaniel and then click on breed club. This will take you to the national breed club and you can go from there.
FWIW - I have always found that a puppy from a
reputable breeder will cost you far less than a pet shop or backyard breeder. Reputable breeders are into it for bettering the breed and not for as much profit as possible. If you breed correctly, such as doing all the health screenings and all the prenatal care, it is pretty much impossible to make a profit off a litter.
Breed club rescues are great as is the previously mentioned Petfinder if you want to go the rescue route.
I would stay away from the designer dogs as these are usually two puppy mill / backyard breeder dogs being bred together for profit. No reputable breeder would allow their carefully researched and bred dog be used to create mutts for profit. So, they only place the designer dog breeders can get dogs without a spay/neuter contract is from a puppy mill. So, buying a designer dog is just really buying a puppy mill dog.
Good Luck in your search!