
BBC has a special about it, called US Elections: The Basics
They started a while ago to cover the information , and it basically has a lot of graphics helping to understand how the process is and how it has been changing. Is more than just reporting, it's educative.
Inside this special there is a section called Q&A, where are the questions and answers about the process, for example, it helps to find out things like: What happens if Democrats lose control of Congress? , What happens if Democrats lose control of Congress?
But the editor selection is showed too, with the section Races to watch. It has the most important races, according to BBC editorial.
Finally, the section which impress more is the one called Predicted result. There they take a risk saying what could happen, and which candidate probably is going to win, backed by expert from few other media:
Charlie Cook - The Cook Political Report
Stuart Rothenberg - The Rothenberg Political Report
Larry Sabato - Sabato's Crystal Ball
Nate Silver - FiveThirtyEight Blog, New York Times
New York Times has also a section about the elections called 2010 Midterm Elections, but it less graphic and has more relevance on the news.