It’s a busy old day on Capitol Hill.

President-elect Barack Obama’s picks to head the Securities and Exchange Commission and the Department of Homeland Security and his nominees for attorney general and ambassador to the United Nations will be on Capitol Hill for their Senate nomination hearings.

The Senate Banking, Housing and Urban Affairs committee will hold a hearing on the nomination of Mary Schapiro as SEC head at 10 a.m. EST. At the same time, Obama’s nominee for Homeland Security, Gov. Janet Napolitano, will be quizzed at a separate hearing on her suitability for the job.

Eric Holder, Obama’s nominee for attorney-general, is expected to be questioned by the Senate Judiciary Committee about his role in pardons granted by former President Bill Clinton, in particular the case of billionaire financier and fugitive Marc Rich.

Clinton’s wife Hillary had a relatively easy ride at her nomination hearing earlier this week. The Senate Foreign Relations Committee will vote today on whether she should be the next secretary of state. The committee will also hold a hearing on Susan Rice, Obama’s choice to become the next U.S. representative at the United Nations.

In the Senate, Vice President-elect and Sen. Joe Biden will deliver farewell remarks to his Senate colleagues. Hillary Clinton, the junior senator from New York, will also bid farewell.

Roland Burris will also officially take the Senate seat vacated by Obama. Burris, was appointed to the seat by embattled Illinois Gov. Rod Blagojevich in December.

Off the hill, President George W. Bush is due to speak at a ceremony at the State Department marking his administration’s foreign policy achievements.

Outside of the Beltway, Obama heads to Ohio to tour a wind turbine manufacturer. The trip is an opportunity to tout his $850 billion stimulus plan, which Congressional Democrats are still working on.