The Office of Management and Budget is a cabinet-rank office within the Executive Office of the President (EOP).  The OMB was organized by the Nixon administration from the previous Bureau of the Budget. Its main function is to assist the president in overseeing the formation of the budget and its implementation in government agencies. 
The management component of OMB oversees personnel, information technology, financial transactions and federal procurement policy-related actions. One of the offices within this side of the OMB is the Office of E-Government and Information Technology (E-Gov), which is headed by the appointed federal government's chief information officer. Click here for a complete organizational chart. Agency officials often elaborate on official memoranda and executive orders with posts to the OMB blog. The OMB website also has interactive features to help citizens better understand the budget, such as this fiscal 2012 budget tool.