I can tell you that (responsible) Poodle breeders start shaving face, feet and tails at a very early age so their puppies are used to the grooming process. While a haircut may be unneccessary, I don't think it would be harmful at all. If you are planning on keeping his hair short, then it's a good training opportunity IMO. I do agree that 10 weeks is too young to go to the groomer though, you should do it yourself or find a mobile/housecall groomer w/ OCD.