We've been using Rotoworld here at WCG for a while now, but they have recently revamped their entire system, and rolled out an amazing database on team contracts.
Every player, on every team, with the exact details of each contract- when it was signed, how much money, how it's broken down and structured, etc. Here is the Bears link... save it to your favorites for easy reference in the future.
Nice work Rotoworld!