You can reach Pyongyang by air from Beijing. If you are traveling with agency (which is 99% of entrance for foreigners) you don't have to worry about ticket, everything is arranged before.
You must check in 3 hours prior to departure (we didn't realize why).
The only care is if you can handle old russian aircraft of Air Koryo (Tupolev or Ilyushin), allegedly all the pilots are army pilots so they can handle any situations that occur during the flight.
Flight attendants are cool, pretty, helpful etc.
Another thing you don't have to think about. During your stay in North Korea, you'll always have your own transportation (usually mini bus).
Local transport in only for locals (you'll see often how electric buses aren't driving due to shortage of electricity). The only time you can use local transport is when they show you 2 metro stations.
You've two choices, a very long and interesting train trip from Bejing, or a short hop in one of Air Koryo's two aircraft. I'd take the train. You will meet some North Koreans on the train (if you try)and it will be the only time you do without your ever-present guide.
Avis do car hire in Pyongyang. And they hire flying pigs as well.
You'll be taken everywhere by minibus, and that's it on the getting-around front. Strolling around to take in the sights is not overly encouraged (i.e you can't do it). This is a picture of the subway, which is the closest you'll ever get to going on it for more than one stop! Note the massively ornate murals created from coloured stone. The stations themselves are a masterpiece of ornate work which are at least as impressive as the Moscow subways. if you want to see a lot more about the metro system, visist the excellent site at www.pyongyang-metro.com