You can access all library databases at this web address: http://library.shu.edu/az.php. On the right side of the page, you will see popular databases. All of these are excellent starting points for political research. CQ Researcher and Opposing Viewpoints will give you both sides of popular issues of today ranging from gun control to immigration.
When researching the US government, you want to know the agency name, political party or topic your are looking for. Are you looking for declassified documents, media coverage or election data? Keywords to get you started might include: a specific bill or resolution, campaigns, chronology, courts, elections, foreign policy, government agencies, Senate, Supreme Court justices, voting records and the White House.