First let me say if you saw either of the I am Legend or Omega Man movies, you owe it ro yourself to read this book.
This book is the start of the whole apocalyptic zombie/vampire genre and in my opinion the best. Nothing since has matched it for not only the horror of the plot but also the humanity of the characters. Yes even the humanity of the vampires comes through. This book is one of the main inspirations for many of Stephen King's novels.
Keep one question in mind as you read this book, "When does what was once considered normal become the abnormal?"
Be ready for a surprise ending.