WASHINGTON – Democratic Rep.-elect Chellie Pingree describes orientation week for new members of the House as being like the first week of school.

“Half of the time is spent finding your way around,” she said.

On Friday morning, Lisa Prosienski, Pingree’s campaign manager and future chief of staff, led the way through the numerous hallways and floors of the U.S. House office buildings exploring potential offices for the new Maine representative and her Capitol Hill staff.

Office picking is an institution on the Hill.

Offices are picked by seniority – the longer you have served, the higher you are on the list. When members retire or lose and their offices become available the current members get to decide if they want to move to a vacated office. Then there is a lottery for new members.

On Friday morning, the new members or their representatives gathered for the lottery, which Prosienski described as “quite a ceremonial process.”

Getting No. 1 means you’ll get to choose first. Getting the last number means that you may end up with one of the offices on the fifth floor of the Cannon House Office Building with no windows and low ceilings.

Prosienski picked number 17 – out of 54 – which she considered pretty lucky. By early afternoon, she and Pingree knew they would be in Room 1037 of the Longworth House Office Building. As Pingree had wished, she will be on a lower floor and will have windows.

Before they can settle in to their new jobs during the first week of January, new representatives and their teams have tons of work to do. The new members’ orientation week was designed to give the freshmen some help in organizing their offices and understanding their new roles.

“A lot of this week has been about administrative and procedural issues,” Pingree said. “We were given stacks of paper and applications. I had been told there would be those things but I didn’t know there would be so many endless details.”

Besides receptions and celebrations, including a dinner below the U.S. Capitol Rotunda and a reception at the botanical garden, the week was more about sessions to learn about pensions and benefits, the rules surrounding staffers, anti-discrimination laws and how to set up an office.

But Pingree said she did have time to think about being in Washington.

“Did we really win? Are we really here?” she said. “It is so exciting to be here. I knew it would be great but I hadn’t assessed the impact of winning with Barack Obama.”

Prosienski, who has been working on and off with Pingree since she ran for the U.S. Senate in 2002, is also eager to be on the Hill.

“It is very exciting,” she said. “This is a tremendous opportunity. I would expect a fast-moving Congress and a lot of work.”

They both are going back to Maine for Thanksgiving, but they won’t have much time to rest. Another orientation session is planned for the first week of December at Harvard University’s Kennedy School of Government in Cambridge, Mass., and they have to work on taking over for Rep. Tom Allen, who lost his challenge to Sen. Susan Collins.

“We have so much work to do,” Pingree said. “We are making a transition, picking up on cases Tom Allen was working on.”

She also has to interview and hire staff – up to 18 members for Washington and Maine offices – study the numerous issues that need to be addressed, build a Web site and learn about communications on the Hill.

Even though the team is still in transition, Prosienski said, she already has received a phone call for “Representative Pingree.” And the BlackBerry Pingree got this week, the “internal communication system” of the Hill as Prosienski called it, is already getting messages.