Now how does one break a quest... I imagine.. you have item X before they tell you to get that item....
Walk up to them, they say find item X....
You keep clicking and it gives you option to give item...
they say Oh you found it!!! Here is your reward...
Do some quests not do this if they become broken?
That is how it is supposed to work, and that is what usually happens. Unfortunately there are quite a few bugs in a game as large and complex as Skyrim.
I encountered such a bug in the companions questline that stopped that questline cold and left Jorrvasker a complete mess with me being unable to meaningfully interact with any of the members. The reason was I had cleaned out a certain dungeon and had not waited 30 days for it to respawn. The companions quest I was supposed to get sent you to the same location, but the boss was dead and the game is supposed to send you somewhere else, but it got confused and jsut held the companions questline in limbo. I had to reload a prior save, wait 30 days and then go back to Jorrvaskar and try to reinitiate the quest. It worked, and I moved on from there.
The UESP does not have a comprehensive list of them unfortunately. If you want to know if a quest is bugged you have to go to the page for that quest and wade through the spoilers. The 1.4 patch is supposed to clean up a bunch of quest bugs. But until it is play tested by millions of people we won't know how successful they were and how many bugs persist.
Save often and keep a good selection of prior saves. That way if you run into trouble, you can reload a prior save and figure out how to avoid the problem with an online reference like UESP.