quests How do you turn into a werewolf and a vampire?

I saw a Skyrim walkthrough book in Walmart yesterday, but don't have enough money to buy it. While I was looking through it, I saw that you could turn into a werewolf or a vampire. Details please?

Where do you find each of these parties? Can you give me the name of the place and area that they should be at or close to? Thanks!

Its not as great as it may sound. I was chased out of Riften when i was trying to get married when i was a vampire (had to delete that save since i hated being a vampire so much) and ive never used the werewolf power since i got it. Only plus is you cant get other deseases

EDIT - i have the walkthrough, its awesome

It's really not that fun, you seem to lose more than you gain by becoming either. I found an amulet that gives me 100% desiese resistance, so now I don't have to worry about becoming some vampire. I will admit though, it is kind of fun raiding a Hold as a werewolf.

Lol, thanks guys. My brother is a werewolf and it's pretty cool, but I wanted to be a vampire. Buuuuut now that you all are saying that I shouldn't then maybe I won't. I dunno. The walkthrough says that being a vampire gives you more strength, so, I really liked that because yesterday I explored these ruins called Myuizk or something like that. Man, there were these machanical spiders and these poisonis bugs in there. They were ok to kill, but the further in I got, I started to see these humanoid machines on wheels and these Smeagol-like things. (You know, that "my precious" guy.) They kept on killing me, so I ran. But I saved when I was running and ended up being killed every time I returned to that save point because there was one of those things right behind me and hit me only once and I died. (I was low on health) So, I will NO do that again. I had to load from a diffrent save point to get out of there.