Paranormal novels need most importantly to evoke the paranormal. They need to have elements of fear, uncertainty and freakishness. They don't need to scare the reader, but there should be something that is not quite right. Just because paranormal novels have become popular doesn't mean they should become mundane. To make the reader interested, try to keep the mystery and fear of the paranormal as part of your story.
With the Twilight series, the Anita Blake books, the Sookie Stackhouse novels and many other recent paranormal works of fiction, it may seem like the genre is over-done. The same could be said about novels about WWII or mother-daughter relations. What saves a novel is its characters. If the reader finds your character to be a weaker Sookie Stackhouse, he or she may keep reading, but probably won't come back for round two. Make sure each character is fully him or herself, with history, motivations, beliefs, faults and strengths. You can write the 100th story about vampires of this year, but if your characters pull the reader in, you will have a strong fan-base.
What sets a paranormal novel apart from a normal novel is that conflict often centers around the fact that there are paranormal activities happening in a normal human setting. Your human characters therefore should not be complacent or easily accepting of events. There should be elements of fear, hatred, in-acceptance and other antagonistic sentiments, especially between paranormal and human characters. This makes the story more realistic, and any resolutions or acceptances that much stronger. Nothing should be perfect, and everything should be believable. The fact that the setting is paranormal adds just another dimension, with which you can work to create tension, conflict and mixed emotions.
The creativity and originality of your paranormal world and/or characters can set your novel apart from the others from page one. This can mean simply creating a new type of paranormal creature or a whole different world with new laws and forces at work. Be careful that the new world doesn't become so detailed and complicated that readers need to write things down just to keep the story straight. The paranormal is often very strong when situated in a human context. To keep your paranormal characters interesting, make them react differently than readers might expect. A story with surprises, richly interesting facts and things to discover is better than a world created simply in order to create one.