http://www.c-span.org/Live-Video/C-SPAN/) & this blog has one of its objectives to discuss practice and procedure in the Federal legislature. The Presidency (and every four years the election process) dominate world news. Even the Supreme Court is regularly mentioned in news and fiction.
But there is more to the USA than the Federal Government. The 'United States' is just that - a nation crafted of the States which created it. In Britain, the Scottish Parliament; the National Assembly for Wales; the Northern Ireland Assembly; and local councils are the creation of the Westminster Parliament. They derive their powers from Westminster - and could be abolished by it. However in the USA it is the States who are the source of Federal authority. The Constitution protects that power. So following what is happening in the 50 individual states is important for a true understanding of 'America'.
Each State has its own structure of government - for example Michigan has a Governor (head of the Executive branch); a bicameral legislature - with a Michigan House of Representatives and a Michigan Senate; and a State Supreme Court. The Michigan constitution can be accessed here.
The Council of State Governments - a nonpartisan non-profit organization in the United States serving the state governments (all branches)
Stateline - news site
The Pew Center on the States
National Conference of State Legislatures