OP, samoyeds are beautiful dogs full of character, but they are a lot of work compared to some others such as retrievers. There's actually a high number of those types of dogs (huskies, malamutes etc) given to shelters because people just weren't prepared for the reality.
They are smart but stubborn so they'll understand commands but choose when to follow them. You need to be very firm and consistent (but loving too of course). If trained and raised properly, they'll be generally well-behaved but don't trust them to have perfect recall when outdoors. They can become destructive if bored/distressed/not exercised enough.
They are good family dogs IF raised well with respect for all family members. If you're too relaxed and inconsistent you'll probably get a lot of disobedience. You shouldn't get aggression etc unless things have gone really wrong.
In terms of barking - I've never known it to be an issue (though it's possible depending on the individual dog, how its raised and things it likes to bark at). They can be vocal though (which is just chatty and not too loud- actually really nice character trait). They can howl if left alone and unhappy about it.
They need a lot of exercise no matter what the weather. Their coats do regulate their temp as a PP said, but they still struggle with heat so you need to make sure you have a shaded outdoor spot and cool area indoors for them. It's not fair to keep them in well-heated rooms with no escape.
The hair is the thing that will shock most people. It's not how quickly it covers your floor (which is expected), it's how much gets on all other surfaces. You will find it in your kitchen cupboards and regularly in your food (the undercoat is very lightweight and the individual hairs float about). This really ramps up when they shed.
They're amazing and if you understand what you're in for and committed, they're wonderful pets. You need to know a thing or two about dog training and be prepared for the maintenance though. If the above is a concern for you, get a retriever - they're not as eye-catching on walks but they are also wonderful, loving pets.