Women's Road Race: from 9am EST/6am PST /15:00 CEST/2pm BST - live on TourTracker
Men's Road Race: 1:15pm EST/10:15am PST/19:15 CEST/6:15pm BST - live on TourTracker
TourTracker has a ton of information about the course (Euros! you can flip between miles and kilometres!) but there's more information on the USA Cycling website - including links to the ways you can watch the Tracker on iPhone and Android, and on tv.
The women's race is live now, and being commentated by 2-times Olympic ITT champion Kristin Armstrong. She's excellent at explaining the racing, and who the riders are, so if you're new to USA cycling, or women's cycling in general, this is a great place to start!