Parcel delivery to Korea (North)
You should be aware that there are some shipping restrictions between the North Korean government and many other countries, such as the United States, around the globe. Many of these restriction are fueled by political unrest, such as nuclear attack threats made by the North Korean government to the United States, as an example. It is advised that you check to see if you are even allowed to ship your goods there before getting everything packaged up as you would not want to waste your time doing such things if it was only to find out you are currently not allowed to ship there.
Customs for parcel shipping to Korea (North)
Shipping to the Democratic People's Republic of Korea is fairly straight forward, assuming you follow their procedures and by laws in doing so. This means that you adhere to their guidelines for what is allowed in the country and what paperwork they require to ship there. You should also be prepared to pay any duty or fee assessed on your particular parcel, based on its value as it will not be allowed to be released for final delivery until this happens, assuming this applies to your parcel. Customs there has the right to inspect all parcels that come into the country and they typically do so.
Parcel delivery limitations to Korea (North)
The main thing that is prohibited from shipping to the Democratic People's Republic of Korea is that of materials (so books, magazines, or other literature, as examples) that the government does not agree with or thinks is divisive towards their message. North Korea is notorious for their censorship so this is a hot bottom when it comes to shipping there. If you are even allowed to ship there from your location, then you will want to check to see if the items you want to send over are allowed into their borders or not. You do not want to go through the trouble of shipping all your items over there only to have them seized by the government and you be out the money and time you spent trying to ship your stuff over there.