How do you sign up?
Check out this video of a skytrain of satellites getting themselves into orbit.
All video taken from the ground
They are suppose to start beta testing in August, you can sign up to receive an email when they start taking applications for the beta at starlink.com. Nationwide rollout isn't suppose to take place until 2021 although the entire system won't be complete for several more years (though much of the later years is simply to add additional bandwith and redundancy).