Source, on the whole, is http://bitcoincharts.com/ You can break down all the numbers yourself. You can also get a giant history table of all buy/sells with times from either bitcoinity or bitcoin charts, I forget which.
http://bitcoinity.org/markets is the place I watch. The table on the right is aggregated buys/sells, so if you see something like "200 for 90.00" it could be 20 people buying/selling 10 coins, not 1 doing 200.