Is this a job for which we need new blood or someone who will work ‘by the book’？

for which we need new blood or someone who will work ‘by the book’是定语从句，修饰job。其中new blood or someone who will work ‘by the book’做need的宾语。who will work ‘by the book’又是定语从句，修饰someone。

The Chinese version of the whole sentence is probably:
这是一件我们需要新鲜血液或一个照章办事的人的工作吗？

by the book是“一丝不苟地按规则；依照惯例”的意思。例如：
He always goes by the book. 他一惯照章办事。
This is a course strictly cooked by the book.
这是一道严格按菜谱烹饪的菜肴。