Forget everything you ever learned about driving!
I live just outside Boston. Everyday I drive through the city, I frequently drive into the city. Now, honestly when I lived in CT I thought that people from MA were horrible drivers. But, then I moved here and realized this is the only way you'll survive.
Here are a few driving rules that I've tossed out since moving to MA.
Stay two-three car lengths behind the car in front of you.
Now I guarantee if you do this you will get cut off by at least two cars. Therefore it is absolutely necessary to drive as close as you possibly can to the bumper in front of you without actually hitting it. Even if you have half a car lengths space, someone will cut you off.
Always use your blinkers to indicate a lane change. Also put the blinker on before you even check to make sure you can switch lanes.
The only way this is ideal is if you never want to get into the next lane...ever. If you put your blinker on, the person in the next lane will purposely speed up so you can't get in front of them. I recommend never using your blinker when changing lanes.
When making a left turn pull out just a little so you can see, and then wait until traffic clears.
If you do this, you'll sit and wait for the rest of your life. I fully believe that if I followed this rule I would still be sitting at an intersection right now. I recommend following the MA standard, which is slowly pull out until you are blocking traffic from going on the left, and when the traffic on the right clears pull out. If traffic on the right doesn't clear follow the same rules for blocking traffic on the left.