This is a phrase asking for verification of statements made on the internet. Due to the anonymity automatically attainable by persons using the internet, often times these persons create characters that do not represent who and what they are in reality. By asking "where them books at" a person is actually asking for pictures or other proof to verify the statements made by persons using the internet are factual and true.
A guy on this message board I visit claimed he managed a restaurant. I asked him "Where them books at, bitch?" and he provided pictures of his user name inside the restaurant's office.
by buk0ne January 14, 2010