
I can only say how I went about it.
Firstly I contacted the owner of the sire of my bitch, introducing myself, letting her know I was interested in researching the pedigree of my bitch.
As it happened this person was the doyenne of the breed, and my breeder was also someone of similar calibre.
I quite unashamedly milked them for knowledge about dog in the pedigree of my bitch they had personally known.
I also wrote to the owners/.breeders of more distant relatives tactfully asking for information, like how long they lived, could I have pictures etc.
I joined our national breed club, and purchased the last 10 years of annuals/journals.
This enabled me to see how various dogs and kennels had developed. I then went back a further 10 years and then got as many old yearbooks as I could.
Fortunately our breed annuals print all the breed registrations, health test results etc, so you can fill all these details for your bitch, and any dogs/lines you admire.
By going back 20 or 30 years you can avoid falling into the trap of admiring what is currently fashionable. You will notice changes or more often a pendulum of what wins, but those a long time in a breed who breed to their interpretation of type will often be producing dogs of a consistent type, whether they win or not.
Attend any breed seminars, especially regarding judging, but keep an open mind as all speakers will have a slightly differing idea about what is correct. Learning about basic structure and movement are fundamentals. Going to breed seminars of other breeds can be quite enlightening too.