
It's also not just about the pedigrees and how much red is on them, as someone else said it's about health (find out what testing is required for the breed you're looking for) and about how they're raised, and the breeders themselves. Someone can breed a litter with lots of red in it, but that doesn't mean they've been raised well or socialised well.
Ask lots of questions, and make sure they ask lots of questions of you. If a breeder doesn't have as many questions for me as I have for them then I would run a mile. I've been on both sides of it as a buyer and as a breeder. I'm not saying that you need to have an official interview. Often in the course of an hour long chat all the things both people want to know are answered. But make sure it's not just about the money.
Some breeders (who breed nice dogs) are quite happy to take the money and run, leaving you with little or no support afterward. So one question to ask is what kind of support they will provide after you take the pup home. I'm on the end of the phone for any of my puppy owners 24/7. I hope they never need to call me at odd hours in the middle of the night, but if they need to then I'm there.
I have a contract that I ask everyone to sign, but well before they get the pup I have emailed a copy to them for them to read and see if there's anything in it that they're not comfortable with (ie endorsements), and I'm willing to talk about it.
So just some examples of things to ask
Best of luck in your search. I hope you find what you're looking for :)