Native speaker me and English dictionaries agree: bookless library is a "real' word.
Nowadays especially, there are many "bookless" libraries". That is they do not have in books printed physical form. These libraries operate solely as digital. Think e-books, etc. In that since they have digital book files.
도서관 = library 도서관은 책이 없어요 = The library has no books. 책이 없는 도서관은 소용없어요 = A library without books is useless.
Moving that ending before the main subject is how you describe the subject in Korean. It's quite a difficult thing to wrap your head around initially. Think about it like adjectives:
파란 공 = a blue ball, 예쁜 여자 = a pretty girl, 맛있는 사과 = a tasty apple.
맛있는 follows the same exact rule as the above sentence but you are likely comfortable with it. When you start to add more detail is when it gets harder. An easy way to imagine it is pointing out someone in a room. You see that guy? Who? The one wearing a red shirt. Now in Korean...: 빨간 셔츠를 입는 남자 (the red shirt wearing guy).
웃는 아이 = a laughing child 빨리 쓰는 학생 = a student who writes fast
Notice I am using -는 every time. That is because it is present tense. I'll leave it there for now.