Answer
362880
Work Step by Step
The number of possible permutations if r objects are taken from n itself is nPr = $\frac{n!}{(n-r)!}$
The number of different ways you can arrange the books, assuming that the order of the books makes a difference to you, is:
9P9 = $\frac{9!}{(9-9)!}$ = 362880 ways