This is North Korea's third largest city and a major centre of heavy industry.
Nothing to Envy, by Barbara Demick, an LA-based journalist, is a partially novelized collection of interviews with six former residents of Chongjin, who later took refugee in South Korea. While the main plot revolves around the lives of six main characters/interviewees before and during the North Korean famine of 1990s and their eventual flight to South Korea, the book has lively depictions of Chongjin and the surrounding area, especially during the economic collapse of North Korea in the 90s, throughout.
Young Pioneers Tours and Koryo Tours, as well as some others, run tours to this area, yet much less frequently than to other parts of North Korea. Usually, you can combine a trip to Chongjin with nearby Chilbosan and Rason SEZ.
You're likely to get around by a tour bus operated by a state run company. However, supposedly, Koryo Tours managed to use to trams and public transport on some of their tours.
Chongjin is a fascinating city, yet it remains very closed off to visiting foreigners, and you'll only be allowed access to a few places. The main square has statues of Kim Il Sung and Kim Jong Il, and tours may take you to the nearby E-Library, which is a very odd experience. There is also a fantastic art gallery just off of the square.
The Soviet Martyr's cemetery is worth visiting, with a fantastic view of Chongjin port and the adjacent old part of town. You can see the sea on two axis from here, and it's quite a beautiful sight at sunset.
One of the highlights of a trip to Chongjin would be to visit the kindergarten performance, which a lot of tours here show. The kids there perform at the standard of trained adults.
Great place to visit is high school oriented to foreign languages. Kids study english, russian and chinese (one or two of those), and are very open and after few minutes not even shy to speak to foreigners. Some of the kids can speak better than most KITC guides for some reason.
The most interesting this to do in Chongjin is just to observe daily life as much as you can. This is probably the more stereotypical version of North Korea as opposed to Pyongyang.
While the average citizen has a hard time surviving, finding food will not be a problem. Food will be provided, and will be better than most of the country experiences.
Local drinking water is known to be untreated. Bottled water is the best choice. Some tourists have been hospitalized in North Korea due to drinking the public water.
Chongjin's Seaman's Club is a popular place for well off North Koreans and tourists often visit too. A foreigner was once arrested here for leaving a Bible in the toilet.
Chongjin Foreigner's Hotel is probably where you'll be staying, although other places may be open to foreigners too.