What is FOIA?
Since 1967, the Freedom of Information Act (FOIA) has provided the public the right to request access to records from any Federal agency. It is often described as the law that keeps citizens in the know about their government. Federal agencies are required to disclose any information requested under the FOIA unless it falls under one of nine exemptions which protect interests such as personal privacy, national security, and law enforcement.
(From About FOIA)
What can I ask for under the FOIA?
A FOIA request can be made for any agency record. You can also specify the format in which you wish to receive the records (for example, printed or electronic form). The FOIA does not require agencies to create new records or to conduct research, analyze data, or answer questions when responding to requests.
Most federal agencies now accept FOIA requests electronically, including by web form, e-mail or fax. See the list of federal agencies for details about how to make a request to each agency and any specific requirements for seeking certain records.
(From FOIA How To)