Everyone needs a visa, and you need to book a tour. North Korea is such a special country that only a few tourists get to visit each year. The visa costs $70, plus you must book a hotel, the cheapest is about $120 per night, and finally you have to deposit $300 per person to a bank in Spain. Oh and you have to fly in which costs $300 per person (from Beijing). Tours start at 2500 euros per person.
There are various travel agents on the internet that cater for North Korea, take a good look around and find one that can suit your requirements and budget.
Israeli, South Korean and US citizens have to visit with special tours and make special arrangements.
Official Site
