I am in Sweden as well, In Stockholm, but I am originally from Australia so maybe my advice will be slightly different to Swedish advice... but here it is. LOL. It's a bit long, as I just wrote this to someone else asking about a biting puppy... :-)
"Hej! B och oss är bra, tack. Bentley är lite rädd på båten men det går bra i alla fall.
Var det du som skrivit en inlägg i Golden Retriever forum om valpar som bita??
Ha ha... ja!! Bentley bett jätte mycket när han var liten. Det är helt normalt för retriever valpar att bita och det är hur de leka och lära med varandra. Man måste tänk liksom en hund... när valpar bita varandra de också "yelp"... like a high pitched short scream. Efter det, hundar ****a att bita för hårt för att de lära att det ont.
So... every time he bites at you or nips at your legs or hands or clothes... yelp like a dog that's just been hurt and refuse to play. Don't pull your hand away too fast too soon because that will only invite him to play more and possibly even break your skin. Those little milk teeth are SOOOO sharp and it will hurt lots of times and leave you with scratches all over your hands and arms, but it's important to teach him it's not okay to nip or bite too hard. Eventually he'll learn to control his jaws. We used a big oven mitt in the beginning to protect our hands. To this day, Bentley still likes to pull Lars' socks off in the evening and run away with them... only now he's much more gentle and the adult teeth aren't as sharp.
By the time Bentley was about 6 months, he had learnt to be gentle... but he still jumped up and nipped... so... this will sounds horrible, but it's honestly not... I nipped him back. I actually bit him on his ear a little and he yelped. After that he never did it again because I spoke to him in his language, so to speak. I didn't hurt him, of course, but he needed to understand it wasn't okay, and that's exactly the way dogs do it with each other.
Once he's had all his vaccinations, make sure he socialises with other dogs, as well. Of all ages, sizes and breeds. The best way to teach a dog is with other dogs, I think. We took Bentley to dog parks as soon as it was safe. It teaches them good social behaviour and older (well behaved) dogs won't stand for nipping or biting, so they learn pretty quickly.
Even now, at almost 18 months, he can be rough when taking things from my hand, like I always have to remind him "gentle" before he takes it, but he always listens and he's even really gentle when we play.
Some Golden's even greet each other by mouthing... this is when they'll actually nip each other harmlessly and some even do it when they meet new people, they'll take someone's hand in their mouth. So it's natural for them to do it, we just have to teach them what will hurt and what won't.
Goldens also have a natural chewing instinct. So they are incessant chewers. For this reason, don't leave around shoes or anything you don't want chewed and make sure he always has something he is allowed to chew on, like a bone or toy.... if he chews something you don't approve of... tell him no, take it off him and replace it with something he is allowed to chew on. This, in the long run, will also limit biting because their need for using their jaws will be met.
All this will be a test of your nerves (I cried many times LOL) but it will all work in the long run and as I said, it's completely normal for a Golden puppy to nip and bite.
I hope this info makes sense... it will take time, but I promise it will work"