I work with a lot of SEO researchers and they make big money. However, you really need to know SEO if you are going to specialize in it. There are a lot of hacks out there and people are wary about who they hire and they will check up on people and their credentials - especially if they plan to pay big bucks.

My advice - learn from a SEO specialist who's been doing it for a long time. Books will only get you so far. I highly suggest you train with real specialists and/or take classes and trainings from SEOs who have been doing this for a long time and will steer you in the right direction.