Shelters in my area won't let you adopt with children under 12. And with good reason. Small children can't handle large breeds, and small dogs are prone to be defensive and startled by kids who are too young to understand that at the end of the day...a dog is an animal...and will behave like one.
And generally rescue dogs and shelter dogs are abandoned or surrendered because someone else couldn`t deal with them. And if you are gone all day...please don`t get a dog. They need you.
Having said that...the local vet is a great place yo find great dogs. Our best shepherd was one we found that way....the owner had to move to Tokyo...loved the dog, and the vet had known the dog from puppyhood.
We have bought from breeders, adopted from shelters, and a great rescue place that places the dogs in homes until they can be adopted. The shelter dogs have had the biggest problems.
We have a fabulous place here..Dairy Dell Canine. Look online. The woman is fabulous. We enrolled our 7 yr old 82 lb dog who had become dog agressive when our Shephard died, into four weeks of boarding school. I am a large woman, and this dog could pull me right off my feet if i had her on lead and a truck drove by with a dog hanging out the side barking. I really thought we were going to have to put her down. Camilla saved us. The dog is still agressive but she is manageable. I can't say enough about good training.