in his room , crooks has a dictionary and a copy of the califorina civil code (laws that do not refer to criminal acts) what can the reader conclude about crooks beacause of this

From these articles, we can infer that Crooks is educated and continues to educate himself. 

Crooks not only has educated himself, he is very concerned with human rights.  The civil code is a legal book concerned with rights and justice issues.  Being black this is an indication of his awareness of the inequities of the laws in the USA at that time regarding race issues.  The mention of it in the book, most likely brings this to the notice of the reader as well.  Subtle but effective.