The law allows for the public to view the records of agencies. Anyone can find out how an agency is spending its money, the reasoning behind their policies, and the intended effect of the agencies policies. Records are defined as final decisions in particular administrative cases, policy statements that the agency uses, but hasn't published in the Federal Register, internal manuals written for the agency's staff that affect members of the public, and an index of the kinds of information that must be made public. The law also allows the public to see other types of records that were not enumerated above and the courts have interpreted this broadly. If you would like to request records under the FOIA, you must submit it in writing to the appropriate agency.
All agencies have a freedom of information officer who processes the requests.
The letter must be as clear as possible stating what information you are requesting and the purpose of the information. Try to limit your request to only the information that you want. If you tell the agency that you just want everything ever related to the subject, you might give the agency an excuse to delay its response, or deny it flat out. Be as specific as possible. Cite relevant newspaper clips, articles, congressional reports, etc.