I've finished Death Note, my first Manga.
I want to read more Mangas but i dont know how I should continue
Go read Angel Sanctuary.
Because I'm such a nice guy:
1) Go here.
2) Enter series you want to read into the search engine.
And I really wanted to get into Berserk. ;_;
Their global search is fucked, the more specific search functions on that page should work though.