Pedigree database is all user based information. I can basically go on there and just make up my own pedigree and put it on there. No way to tell if the information is correct or not. AKC is more legitimate, so that's what I'd go by if I were you.
To register with the AKC, you're going to need official registration papers from the breeder for your specific dog. Do you have those?
To put the pedigree on pedigree database, just sign up and put in the information yourself.