Your job today: Vote knowledgeably

TODAY IS Primary Election Day in Pennsylvania.

The marquee matchup is the Democratic presidential race between U.S. Sens. Hillary Clinton and Barack Obama.

That race has overshadowed the rest of the ballot, which includes contested races for state treasurer and - in Philadelphia - for eight state House and one state Senate seat, all on the Democratic side.

There are also two ballot questions in the city, one raising the number of top-level aides that Mayor Nutter can hire, and the other dividing the duties of the city representative's office.

Before you vote, here's information you should know:

* Polls are open from 7 a.m. to 8 p.m., though anyone in line when the polls close will be permitted to vote. You can find your polling place in today's Daily News on Page 27, by going to the Committee of Seventy's Web site found at http://seventy.org/cac or by calling 1-866-268-8603. If you see trouble at the polls or have a complaint, you can call the group's hotline at 1-866-OUR-VOTE (687-8683).

* You can vote only for nominating contests in the party with which you are registered. All voters may vote for the ballot questions.

* If you are a first-time voter, you must have a valid photo ID. Any non-photo ID must include your name and address. It is not necessary to bring your voter-registration card. To see what kinds of IDs are acceptable, go to the Department of State's Web site, www.VotesPa.com.

* In addition to voting for Clinton or Obama, individual delegates pledged to them are also on the ballot. But, regardless of the delegate vote totals, your candidate's share of delegates in your congressional district will be proportionate to the popular vote for the candidate himself or herself. The only thing the tallies of individual delegates affects is which delegates get to go to the convention.

* If you're still undecided or want to get more information about the candidates, you can go to the League of Women Voters' Web site located at www.palwv.org/philadelphia and read the group's Voters Guide. You can also find the latest primary news at www.philly.com/

philly/news/politics.

* You can truth-test TV ads at www.factcheck.org . You can find out how the candidates voted on key issues and see how various interest groups rate them at www.votesmart.org. To track campaign finances, go to: www.

opensecrets.org/pres08/index.

asp?cycle=2008 *

Staff writers Dave Davies and Gar

Joseph contributed to this report.