The Vampire Chronicles series by Anne Rice?

The Vampire Chronicles follow different vampires and tell their life stories, etc. The first book is Interview with the Vampire and it is very depressing. The books are not easy to read, but they are really well-written. I warn you, this is not a typical vampire series. There will be few happy Twilight-ish endings, there is no sweet vampire romance, so if you like that kind of thing, you may not like Vampire Chronicles. The characters are deeper, and the content is much more graphic and somewhat disturbing. Also, the series is on indefinite hiatus, due to a personal decision by Anne Rice. She has recently returned to the Roman Catholic church and no longer wishes to write about vampires, witches and other creatures of the night. Rice claims that she will write no more Vampire Chronicles books, not even to wrap up the series. You should read the books for yourself though!

"The Vampire Chronicles is a series of novels by Anne Rice that revolves around the fictional character Lestat de Lioncourt, a French nobleman made into a vampire in the 18th century"

That's the Wikipedia description of the series, since I haven't completed the series since I'm only on the first book, but for me I don't think they're hard at all.

In the first book "Interview with the Vampire" Its about a guy called Louis who is turned into a vampire ( by Lestat). The title says it all, since the story is about someone interviewing Louis about his life, but I personally so far am really liking the story, and its easy to forget that the interviewer is there since he's being quiet most of the story.

Hopefully the rest of the books are as good as well, and since there's quite a few books in the series it should keep you busy :)