The best graph we've found for understanding the tax cut deal comes from the White House.
The White House put out this chart today to defend its tax deal with Republican lawmakers (which got a lot of lefties riled up). Granted, it may not be the most impartial of sources, but this is still one of the best charts out there so far for understanding the broad contours of the deal (and I've seen a few).
The White House blog covers a few of the main bullet points of the deal. If you want more (and, perhaps, more impartial) information, I'd suggest Ezra Klein's blog. He's been covering the issue from everyconceivableangle.