How old should I be to read the Wizard's First Rule?

I saw The legend of the Seeker T.V series and I really want to read the books by Terry Goodkind. I read 'Twilight (I hated it but I had to finish it for some reason, idk.) and 'Eragon.' Trust me I read LOTS of other books, lol. I am in 7th grade going into 8th (school ends this Friday :) I am 13 years old (14 in 3 months. [so close yes so far, lol] :) So am I old enough? The only reason I am asking is because on Hulu.com the comments say that the books are really dark and gory (which is the kind of books I love, trust me, it just that it says they are for 'mature readers,' whatever the heck that means. lol.