Use of 书 or 书籍 for 'books'
牛(cow) and 羊(goat) are both farm animal; The term '牛羊' is a general term for 'farm animal' including sheep, horse and all others farm animals.
刀(knife) and 剑(sword) are both cold weapon; The term '刀剑' is a general term for 'cold weapon' including axe, spear and all other cold weapons.
书(book) and 籍(record) are both bound written material; The term '书籍' is a general term for 'bound written material'.
To classify written materials more strictly, novel and textbook are 书,  not 籍; Accounting book and record book are 籍, not 书. The term '书籍' refers to everything in book form, including dictionary (典) and all other bound written materials.
In modern Chinese:

'书籍' is a general term for 'book'

'书刊' is a general terms for 'printed publication'

'书册' and '书本' are general terms for 'bound printed material'


Examples of when to use '书' and '书籍' in sentences:


这是一本园艺书 (this is a gardening book)

所有园艺书都在这里 (all the gardening books are here)

有关园艺的书籍都在这里 (all the books related to gardening is here)



In #1 and #2 you can use 书 or 书籍 interchangeably, but most of the time people would choose to use one less character and just say XX书 instead of XX书籍
In #3. you can also use 书 or 书籍 interchangeably, but the more general 书籍 is preferred because a reference book or a novel might also relate to gardening.