There are two newspapers available which chronicle events and issues on Capitol Hill. The first is Rollcall http://www.rollcall.com/
This appears a number of times a week (dependent upon whether Congress is meeting). There are a number of columnists who regularly contribute - my personal favourite being Norman Ornstein.
The second is The Hill http://thehill.com/. Both are respected specialist publications.
The Washington Post also includes good coverage. http://www.washingtonpost.com/
Congressional Quarterly is another good source http://public.cq.com/