Skyrim is my first of The Elder Scrolls games and i was wondering how the respawn system works. For instant, i killed the blacksmith in Riverwood yesterday by accident and unintentionally killed his wife too. Do they they stay dead the remaining of my quest, or do they respawn at some time?

In case you wanna know, i'm on the PS3 system.

You killed an entire family by accident? A jury of peers will find that hard to believe.

Dead is dead. This is not World of Warcraft.

The only NPCs that respawn are the Generic ones, Bandits, Necromancers, Assassins and the like. If they have a name, and you kill them, then they are gone for the game.

Also, most named NPCs are part of quests, or sources of quests, or sources of commerce or other in game items so it is not always a good idea to kill them. The game will give you plenty of enemies to kill, no need to kill townspeople.