● "If I want to breed a pair of german shepherds, should the puppies be..."
Wrong question, showing insufficient awareness to even THINK of being a breeder yet.
□ Step ONE:
LEARN about the breed so you:
(a) know its name (Deutsche Schäferhund, which translates as German Shepherd Dog - 3 words in the proper noun, so 3 capital initials required).
(b) know WHAT the GSD was developed to do.
(c) know its International Standard http://www.fci.be/Nomenclature/Standards/166g01-en.pdf almost off by heart. If you are in Britain, Canada, the USA, then what's published in your nation is a REBEL document invented in that nation, with the limits and all or most of the DisQualifications removed. Trying to produce a GSD based on any of them is like trying to build a Lamborghini based on the blueprint of an SUV.
(d) know which of a GSD's charms/talents are the ones you most wish to promote (but do NOT ignore any of the other charms & talents - otherwise you'll be producing pups that are only PART of a GSD).
□ Step TWO:
Buy a bìtch with the best pedigree you can afford, after making sure that:
(a) her breeder's previous litters have a record of success for their buyers in whichever aspect YOU are most interested in (I hope you don't see show-is-all as the main purpose).
(b) her breeder supplies a printed & signed Guarantee stating the compensation you will receive if any genetic problem arises in the first few years (see http://lesp90.wix.com/lorelei-gsd-kennels#!guarantee/cyaq and http://sequoyah-german-shepherds.com/warrantee.htm for examples) or disease in the first 7-8 days.
(c) her parents and grandparents possess all the certificates listed in https://groups.yahoo.com/neo/groups/The_GSD_Source/links/all/Defining_a_GSD_001261993982 (you'll need to Join that group in order to access its Links, etc).
(d) her breeder is happy to sit with you for hours, discussing the breed and the good & bad traits produced by the ancestors. Ideally, the breeder should be happy to answer later questions by phone, or within 24 hours by e-mail.
Sometimes an adult is available still young enough to have one litter for you. Make your decision based on (1) the record of her progeny, and (2) her personality - a GSD should live until at least 12, some reach 15 or 16, so you need to LIKE her behaviours & personality throughout her remaining years.
My preference is to bring home a pup at 7-to-9 weeks old, so that I have time for all the familiarisation-&-confidence-building experiences pups need before they reach 13 weeks old. NEVER buy a pup aged 11-to-18 weeks old - its breeder doesn't care about (or doesn't KNOW about!) the developmental stages of pups!
□ Step THREE:
▪ Stay home 24/7 helping Pup settle in and OBSERVING her during the first week or fortnight. And follow the breeder's Diet Sheet for at least the first week, so it doesn't get a tummy upset while still learning to trust you and you are still learning its signals & timings for "Wanna go toilet".
▪ Work out how to be so attractive that pup willingly comes when you call, and willingly brings a suitable-sized ball or toy to you. (At 2½ years, my Bea http://www.pedigreedatabase.com/dog.html?id=1325022 still enjoys "teasing" me by turning her head away if I try to take her ball before she is ready to place it in my hand.)
▪ Once Pup trusts you to protect it, start supplying the safe & fun (in PUP's opinion!) experiences of every movement, scent, sight, sound and texture on your property.
▪ Book in to a proper training club so that there will be a space reserved in its classes for YOU to start getting coached when Pup is 19-to-22 weeks old.
▪ 2+ weeks after the vaccination usually given at 8 weeks, DRIVE pup to places where dogs do NOT run free, do NOT piddle-poo-vomit (spreading viruses), and continue adding safe & fun experiences.
▪ At shows, look for a knowledgeable old-time breeder who might be willing to be your mentor and inform you of the drawbacks in your bìtch's pedigree and in the lines of whichever studs have "caught your eye".
● "1) Purchased when they're around the same age? And 2) From two separate separate breeders to prevent inbreeding?"
DO NOT buy a dog.
Be aware of Les's Law:
"The best mate for your pooch belongs to Sum Wun Elss."
People who have a fertile male tend to use him, regardless. Real breeders don't seek cheap litters - they seek correction & improvement, Those willing to pay stud fees and take their brood to the best stud in their nation for producing whatever she needs improved, produced GSDs such as
https://www.pedigreedatabase.com/german_shepherd_dog/dog.html?id=433761
https://www.pedigreedatabase.com/german_shepherd_dog/dog.html?id=71
https://www.pedigreedatabase.com/german_shepherd_dog/dog.html?id=396411
Notice how their breeders kept their kennel-name going along the bottom of the pedigree, but used other dogs in the tail-male line.
You have to start somewhere, so start with a bìtch. And be prepared to neuter her and start again with a different bìtch, if she fails any of the certificates. You need to keep your numbers low, so that that you can give each one the individual attention all GSDs crave/need. And as GSDs live for about 12 years, if you breed from your first bìtch when she is 3, 4, 6 years old and keep a daughter from each litter, by the time she is 7 you will have 4 bìtches and be ready to start breeding from her daughters. By the time she is 11 you will be ready to start breeding from her grand-daughters.
And although I'm glad you haven't chosen a Best Answer yet, you really SHOULD choose one now - a well-asked question should attract a great answer in its first week, and yours is now 3 weeks old.
Add
https://group.yahoo.com/neo/groups/The_GSD/Source/
to your browser, so that you can easily look up all sorts of information about dogs, especially GSDs.
"Thanks to" Yahoo's /neo/-nut programmer, the settings have been changed from "Open" to "Restricted", so you'll need to apply to join instead of getting instant access to the Links
To discuss GSDs, join some groups such as
https://groups.yahoo.com/neo/groups/GSD_Friendly/info
The people in them KNOW about GSDs. Plus you can include actual photos in your posts.
King Les The Lofty - first pup in 1950; GSD breeder & trainer as of 1968