if  you  are in someone's good books,he is  pleased with you .if you are  in his bad books ,he is annoyed with you .now you can see the phrase "be in someone's good (bad) books"means "have (not have)his favour or
approval".
希望能帮我翻译一下，谢谢！！！！

我觉得应该可以意译为"如果你给别人留下了好的印象,那么他对会你很满意;反之,如果你给别人留下的是不好的印象,那么他会觉得你一无是处.因此你可以由此明白   be in someone's good (bad)books 意思是得到(得不到)某人的喜欢或欣赏."随便翻译的,请别见笑

谢谢~！！！！