Remember Falanu Hlaalu from Oblivion?
... remember that question she asked you?
My PC didn't have enough gold to pay the fine.
I've always maintained that it is sinister that the only pieces of information your character knows about Cyrodiil off the top of his head is the penalty for graverobbing (your journal notes offhand that graverobbing = death in a quest) and the penalty for necrophilia. Everything else, he has to be told, but those, he knows. That is probably why you were in prison in the first place.
As for my character, he will be there for murdering an Argonian. A species who cannot take the moral high ground, ever again.
Start as you intend to go on: Kill a big lizard.