Here's where I started: http://www.creationkit.com/Video_Tutorials
This.
Also "complicated" quests aren't actually as complicated as you might think, or simple quests can be pretty complicated.
My small quests are complicated in my opinion. For example, I have a quest to kill 3 mudcrabs at Zenithar's Shrine. Each one has a script attached to check if various conditions are met, before it advances the quest, using a mixture of different quest stages.
(Probably just tooting my own horn there

)
But back on point. A "complicated" quest as you see it is just a simple set of events, with cool bits slot into various parts. Once you learn how to do things, like activate objects, use triggers, enable/disable objects and actors, create traps, check player stats, use variables.... all of which can be learned on their own, you can then make an easy A-B-C-D quest into a much richer A-1-2-3-B-4-5-C-6-7-D quest. Simply by adding events and scripts you've learned to give your quest some coolness. So instead of just go to this place and kill this guy, you can have ambushes set up at certain points... for example.
Hopefully that makes sense
