You either Randomly get bitten, when you are sleeping in a non-secure location. (eg. Beggars bed, Arena beds.) or ask the vampire in the dark brotherhood once you have finished getting assignments from him.
You can't become a vampire, period. They do not exist.
you drink alot of blood
You can't! You have to get Nightlife!
well, there are certain downloads that can turn your sim into a vampire.
it suprises me some people have such interests in vampires. you cant become an abnormal super human such as a vampire or wolf without getting bit,cut, or killed and awoke to be a vampire.
It can't happen. It is just a story.
Shivering Isles is an expansion pack to Oblivion, and can't work without it.
without mods? no
Drink someones blood while they are asleep.
No.
you cant in oblivion without a mod