Go into tutorial mode, break the bookcases that are already there. combine the books with wooden planks to make a bookcase.
3 Books + 6 wooden planks = bookcase = achievement
Not so easy way:
In normal play you need sugar cane and leather in addition to wooden planks.
3 sugar cane = 3 paper (you need 9 sugar cane total, which are near water)
3 paper + 1 leather = 1 book (you need 3 leather total, cows have that)
3 Books + 6 wooden planks = bookcase = achievement satisfaction you didn't take the easy route.
If you feel like I am missing something, let me know.