A graffiti term which means to sketch. 'Hit' refers to the act of practicing tags, throws, straights, pieces etc. with a writing utensil and 'the books' refers to a black book, sketch pad, or anything to draw on.
This term can also mean reading up on knowledge. Wether it be knowledge of other graffiti writers or knowledge in the form of a video or movie.
My tag looks trash, I need to hit the books and make a new one.