Want to know about the workings of Parliament? The House of Commons Library publishes research papers and standard notes on the parliamentary website. I have found these to be of a consistently high standard - and a superb tool for research - and just learning more.
You can access the service here.
The Congressional Research Service - which also has high standards of independent research - doesn't publish directly to the public. However OpenCRS republishes many of its papers. OpenCRS can be accessed here.
Whether you are a student (particularly of Law or Politics); or interested citizens - there is much available from these sites. In the UK they are covered by parliamentary copyright - however in the US some companies take CRS reports and resell them (except they never bought them in the first place) to businesses and the public. Don't be cheated out of your cash by these people!