
Hi. I have and have had golden retrievers for the last 27 years, and by no means an expert as they have all been pets rather then show or working dogs.
I'll try and answer your questions as best I can.
I feed my dogs on a good quality kibble, currently Arden Grange. You will need to check ingredients making sure there is a named protein such as chicken etc and there are no meat or vegetable derivatives or additives. Or you can feed your dog on a raw food diet. I don't although my dog gets some raw bones a few times a week, but there is lots of information available if you decide that's the way to go.
The average hip score is just below 20 for Goldens. That is the total for the hips which will be expressed as 5/6 (equalling 11) for example. The lower the better. Also elbows are best scored and it's preferable that those are 0. Also eyes need to be examined annually for Progressive Rentinal Atrophy (PRA) annually under the BVA/KC scheme. It's not just about health tests, temperament is equally as important and I spent a lot of time talking and meeting breeders and their dogs before I finally selected 'the one'. I have a very friendly and gentle young dog who is a credit to her breeders.
Check out the breeders in your area on the Champdogs listings and contact them. Try and get to see them and their dogs and see how the dogs react to strangers coming to their house. The best breeders will welcome you and help you as much as they can to make the right choice of dog for you. I had a choice of four puppies this time who temperamentally were all very similar. In the end I took the advice of the breeders wife who had spent the whole of her time with the puppies and had come to know their characters. So far she has got it right for us with our girl.
Goldens seem to spend the entire year shedding their coat having a couple of periods when they shed more then at other times. You need to get your dog used to being groomed (and being washed down after a muddy walk) right from the very start so that you can keep the coat in good condition and free from matts. At the moment my pup has more of less finished her winter moult as she only has a slight coat at the moment. This year she will grow her adult coat and will require more frequent grooming then she's having at the moment. I don't have her professionally groomed although there may be occasions when I will take her to a friend who is a groomer and a golden breeder to have a proper going over. I normally keep her tail trimmed to stop it picking up twigs and leaves, I thin out the more profuse hair at the back of the dog (her bottom) and snip away the excess hair on the paws and keep her leg feathers more neatly trimmed. A Goldens untrimmed feet are like sponges and can bring a lot of mud and water into a house.
For grooming I use a dog rake which gets the undercoat out very easily. Not used a furminator so can't comment.
Goldens are lovely dogs, intelligent and easy to train, however if allowed to get away with things they will exploit that. Go to training classes to learn the best techniques and to socialise your puppy. They are sensitive souls and can get upset with hard treatment, I've found a displeased face is enough to floor my dogs and I rarely need to shout. As they love their food, they respond well to a reward style of training or clicker training.
Any further questions I will do my best to answer.