What special group advises the President?

Answer 1

Traditionally, the answer is "The Cabinet", the group of the heads of certain major departments, known as secretaries, of the Executive Office (15 currently, though subject to change via legislation), plus the Vice President. The secretaries of State,Treasury and the Attorney General still play important roles and if military action is going on or is being considered, the Secretary of Defense becomes important. The others secretaries make few big decision and rely heavily on civil service employees to take care of the duties of their departments. The president would call on the Secretary involved if a problem came up in his area and they make routine reports to the President, but the entire cabinet rarely meets. If trouble with some foreign country arises, the President would probably consult its ambassador and/or appoint a special envoy to gather information.

Today, the two major groups which advice the president are the Staff of the President and the National Security Council. The former handles mostly domestic and diplomatic issues, including political strategy, while the later advises on matters regarding National Security (mostly military, but also a variety of police and general foreign policy/security issues).

For more information about groups which frequently provide advice to the President, go to the source - the White House web site itself is very informative.