Four of the major cities are Chernogorsk, Elektrozavodsk, Berezino, and Stary Sobor. All of these are generally dangerous because of their size, and the amount of zombies and players.

Chernogorsk can be recognized by the massive amount of apartments just northwest of it:

Elektrozavodsk has two firestations and a schoolhouse:

Berezino is the largest city in the northern part of the map:

And Stary Sobor has a giant lollipop (water tower) in it:

If you get to an area where the landsape just cuts off into basic looking terrain, then you are most likely at the debug zone. It's a good place to keep away from players, but there's almost no food for quite a ways.

The Three airfields are Balota, Northwest Airfield, and the Northern Airfield. All of them have relatively good gear, but there are some issues with the first two. At Balota, there are a lot of players who hunt Bambis (newspawns) that are trying to get some decent starting loot. As for the Northwest Airfield, there are many people that try to go there to get good gear, so most of them are hostile. The Northern Airfield on the other hand, while it may have less loot, provides a safer alternative to the other airfields.