http://www.uesp.net/wiki/Lore:Aedra
The light side. The Daedra are the dark. More or less. I'm a bit new to the lore myself. Here's another one.
http://www.uesp.net/wiki/Lore:Gods
That's actually a really black and white thing to say. When it comes to defining sides, it is really a grey area with most of them. However, the Aedra tend to look out more for the mortal races, while the Daedra are more self serving. Only a few of the Daedra are consistently evil, Mehrunes Dagon, Molag Bal, while some of the others just look out for number one. Some, like Azura, actually work much the same as the Aedra do, looking after mortal races and affairs.