The first is called Twilight (German: Biss zum Morgengrauen) and the second New Moon (German: Biss zur Mittagstunde). (The links go to Wikipedia and there are spoilers!!!)
A third (called Eclipse) is planned as well as a movie adaption.
It's about a girl, Bella Swan, who moves to a little town called Forks where she meets Edward Cullen, a charming and myterious young boy. In the beginning it seem as if he hates her but throughout the story it's revealed that he's a vampire and Bella's blood calls him.
I love, love, the way Meyer writes as well as the characters. Especially Bella and Edward ^^
If you're interested, there are a few communities dealing with the books:
- twilight_byte - a newsletter
- twilight_book - dedicated to the books
- twilight_series - a general site
- heroin_blood - a Edward/Bella community
And of course the site of Stephenie Meyer -> http://www.stepheniemeyer.com/