Just ask anyone you're doing business with in the Boston area. Everybody knows how to get to Foxwoods, or Mohegan Sun, both are relatively near one another.
If you get confused, just find I-95 south towards Providence, RI and follow the signs. It's possible to make it in two hours, but then again, Boston traffic can be a bear!
I wouldn't recommend the bus thing, I like to know I control when I leave.