Here are some tutorials found from various sources

• Quests tutorial from Runic Games GUTS wiki
• Kelintor's Quick Quests Tutorial

Quest Controller Objects

• Quest Controller Object
• Quest Flag Controller Object
• Quest Description Controller Object
• Quest Item Controller Object
• Quest List Controller Object

Hopefully at some point this whole section can be expanded / re-organized to be much more systematic, but for now we'll just preserve any tuts we can find ;)