Earth: Home of the Earthlings, this is ground Zero where everything happens. There are a few things to do here.

Namek: A very pleasent place to be, nice place to grow beans.

M2: Where all the robots are, not much to do here.

Arlia: A very arid place, you can find all sorts of things at this dump.

Yaderatt: A weird place, has a school to learn various attacks and techniques.

Space Station Freiza (SSF): Freiza's personal Planet to train people.
 
Vegeta: Where the Saiyans come from.
 
Kaioshin: A place filled with many people, contains many legendary things here.