What does Prospero say regarding his love for study and books?

Initially, Prospero prizes his books above just about everything else. Indeed, his love of books and study helps to explain why he was deposed as Duke of Milan. He was so engrossed in his studies that he didn't notice his own brother scheming and plotting to have him overthrown. Thankfully, Gonzalo, King Alonso's wise counselor, was good enough to ensure that Prospero was allowed to take with him into exile some of the fine volumes from his extensive collection:

By Providence divine. Some food we had and some fresh water thatA noble Neapolitan, Gonzalo,Out of his charity, being then appointed Master of this design, did give us, with Rich garments, linens, stuffs and necessaries,Which since have steaded much; so, of his gentleness, Knowing I loved my books, he furnish'd me From mine own library with volumes that I prize above my dukedom (I.ii).

Prospero's books aren't simply a source of enjoyment or intellectual nourishment; they are essential to the exercise of those magic powers with which he rules over the island. But once Prospero has renounced his magic island kingdom to return to the duchy of Milan from whence he came, he no longer has any need of his magic books, which he will now throw into the sea:

But this rough magic I here abjure, and, when I have required Some heavenly music, which even now I do, To work mine end upon their senses that This airy charm is for, I’ll break my staff, Bury it certain fathoms in the earth, And deeper than did ever plummet sound I’ll drown my book (V.i).