
It's possible if the dog has already produced a litter. Bitches can be maiden, but dogs need to have already produced a litter.
It's a lot of DEFRA red tape and faff. I was going to import semen from Sweden, but by the time I looked at all the intricacies and costs involved it was going to cost me just as much to go myself as it would to import, so I changed track and will be heading over sometime in May or June.
There are a few companies that will assist you with the information you need. One is Fit and Fertile. I can't remember the others off the top of my head as my emails with them are on my main computer and I'm on my netbook now, but there were about 2 or 3 others that I got a really good feeling about. If you do an internet search, I think I did something like 'importing canine semen'.
As for registering, as I said, it's do-able if the dog has already sired a litter. You would need to fill out the appropriate Kennel Club form for registration of an AI litter (do a search on the KC site and it is there - if you have trouble let me know as I think I still have the form filed on my computer). If the dog has his ATC number then you wouldn't need anything other than the registration forms signed by the owner. If he doesn't you will need to submit a 3 gen pedigree and a few other things (these can be found on the KC website as well to do with registration of an overseas sire) and I'm sure others will come along soon who will have more specific info than that. The pups will need to be registered by post - not online due to the overseas registration.
Oh, and to import semen the dog must have his PETS Passport for the semen to travel otherwise it will need to be quarantined for 6 months.
Hope this helps to give you a starting point. I'm sure others will be along soon who've actually done it rather than just researched and given up on the idea like me LOL