Foot in the door

I have recently started a new job as Sr. Network Engineer working for the government. I have a total of 9 years of collective IT experience. I am a CCDP (Cisco Certified). I have been on the job now for 3 months. My question is, what is the bestway to break the ice with the “good-ole-boy network” so that I can get information/documentation to just do my job? My position requires that I interact with this group in order to determine the needs of our infrastructure. Some of the members in this group won’t even return an answer to emails. I need to mention that the group that I’m working consists of middle-aged white men, that are not certified, but who have years of valuable knowledge and experience.