Here is a conceptual diagram of how the universe would look from outside.
The circle in the middle represents the universe with the North, South, East and West
sections being in different colours and the holy area of the universe were the Gods live
being in the middle.
In the East section of the Universe there are 4 galaxy's. As I have said above all of the action takes place in the North galaxy except for a brief period in movie 8 were they fight "The Legendary Super Saiyan Brolli".
Akira Toriyama once drew a map of the North Galaxy in the East section. I unfortunatly do not have the drawing at the moment but will get it as soon as possible. The picture is abit vague and shows the universe in a glass like ball. On it it shows Heaven, Hell, Snakes' Way, the Kaio's Planets, the City of Hades and Dai-Kaio's planet. In a seperate ball he also has the Holy area where all the Kaio-Shin's planets are.
Heaven is a beutiful planet. The weather is warm all year round and all the people who did good with there lives get to go here.
Hell is a horrible were all the worst people are sent Goku has been here once in the TV show when he fell of Snake road. The people who go here are not allowed to keep there bodies and the place is run by 2 deamons called Gozu and Mezu.
Snake's Way is a long and winding road that leads to North Kaio's planet or King Ki as he is called. Goku visited here when he was killed by Piccolo to kill Radditz.
The Kaio's Planets are where the seperate Kaio's who control a section of the North galaxy live. We only see King Ki's planet and the gravity is 10 times as powerful as Earth's. Goku trains here for awhile waiting for the Saiyans Vegeta and Nappa to arrive.
The City of Hades
The City of Hades is were everyone who dies goes to have there souls judged by Emma-Daio. Based on what they did in there life they get sent to Heaven or Hell. The heavenly airport is in the city of Hades and everyone going to Heaven takes a plane to the planet.
All the best fighters in the North galaxy go here to train with other great warriors. The planet is situated above Heaven and is ruled by the most powerful Kaio in the Galaxy the Dai-Kaio. Occasionaly the Dai-Kaio holds a fighting tournament between all of the best fighters and who ever wins gets to be trained by the great Dai-Kaio himself.
The Holy Area
The holy area is the area in the middle of the universe all the Kaio-Shins and higher Gods live here on there own planets. There are three planets and the best one is called Kaio-Shin-Kai. No human or even the Kaio's have stepped in the holy area.