@YourRubyHiker Of course, always happy to answer questions.
So, the rule of thumb is that a good breeder will ask you as many questions as you have for them.
In general they will want to know, (A) Why you have chosen that breed, (B) What sort of life you can provide (exercise, companionship, stimulation etc, (C) Who is in your home (children, babies, adults, other pets, (D) Any dog experience you have (this does not always mean ownership, but can mean friends/family having dogs, or growing up with dogs - if you have a child they will probably want to know what your child is like around dogs, (E) Some many ask if you plan to castrate or not.
When you speak to them, you should ask (A) If the parents are both fully health tested (not all breeds do require health testing - so do your research beforehand, Champ Dogs and KC are good for this and be mindful of what scores are considered 'good' and what scores are a risk for a future puppy), (B) If you can see copies of the parents health tests if you visit the puppies, (C) how many breeding bitches they have (I always say this, but breeding a litter well is exhausting - I sleep by the whelping box for 8 weeks, and I practically throw the puppies at their new families on week 8 because I am so tired - so anyone breeding more than once a year, or once every few years just simply cannot be doing it properly, (D) Why they chose the stud they did (was it his health scores, or was it because he was handsome - ideally you want someone who chose based on temperament and health), (E) How many litters mum will have (no more than two - this is because bitches should not be bred from before they are 2 but ideally 2.5, and no older than 5. 5 is okay, but 6 is not) So, if they don't breed the mum until she is 2, and then have three litters...that's basically a litter a year, which is not good for the dog.
If you're happy with the answers to your questions, and they're happy with your answers, you should meet the litter. Around 6 weeks is usual for a first meeting. Use this as an opportunity to look at how the breeder interacts with the puppies - if they get boisterous or one is clearly unhappy, does she separate them? What about mum? Does mum watch them and give them attention? Don't be alarmed if mum tells them off - it looks vicious, but it very rarely is. A good mum and breeder will install boundaries in the puppies. A good breeder will also makes sure the whelping pen is clean at all time - constantly wiping up any wee or poo. By six weeks, Mum should be attentive but not overbearing - she may jump in and out of the whelping pen. Mum (and any other adult dogs) should want to meet you. She should be friendly and welcoming - not cautious. Likewise, puppies should all scramble for attention and not be scared. Some might not come over because they'll be eating, or sleeping, or playing with each other - that's fine, just as long as they don't seem to be scared or timid.
Check what sort of socialisation the breeder has done (hoovers, people, household objects etc).
Really, it all sounds a bit like common sense but when people view puppies for the first time all common sense leaves the building - and it's understandable as they are adorable!
Some breeders (like me) match puppies to a family based on what they think is best. Remember, a good breeder will likely have spent 24/7 with the puppies for six weeks...they should know the puppies like the back of their hand. You will spend, perhaps, six hours with a puppy before you take it home - possibly even 2/3 hours before you pick one. Seek the breeders opinion.
Most of all, don't be afraid to walk away. People always struggle with this bit - because they've seen the puppies and they want one - but if anything feels off, or even if you just think that litter isn't right for you, then walk away.