Does everyone know about www.electoral-vote.com?
I went there daily in 2004 and found it very useful.
On it is a map of the US and (currently) all the races in play for the Senate.
It categorizes each race as Dem, GOP, Weakly Dem, Weakly GOP, BArely Dem, Barely GOP, and tied, based on the most recent poll.
If you place your cursor on a state, it shows the most recent poll results.
Then if you double click on a state, it shows graphs of each polling organization that give results that go back as far as that organization has data.
So you can get an idea about trends from each poll.
If you go to the bottom, there are House projections, and links to the details, as well.
The page is updated every day.
It's a must-see for political junkies, like me.