hit the books!

Idiom: "(to) hit the books"

Definition:

to start studying

Examples:

1) You better stop partying and start hitting the books if you want to get into college!

2) I need to hit the books and get ready for my test tomorrow. 

中文解释：http://www.youzienglish.com/main/idiom_of_the_day/to_hit_the_books/cn/