Launch Box blog, there is a summary of what's going on along with pictures of all the mess on the street.
Also on that blog, they've put together a great Google Map where you can follow the progress of the boring machine. The map also has pictures of the new station locations and some of the major construction sites, like the launch box itself where the tunnel boring machine took off from earlier this year. Currently, it's chewing its way through granite about 100 feet below 79th Street. It has about 15 blocks to go before it will turn around and start boring it's way back up Second Ave next year.