Mentoring: 10AM to 1PM Saturday, 01/25
Sprint: 10AM to 4PM Saturday, 01/25 and 10AM to 2PM Sunday, 01/26
Q: Do you have to be a "programmer" to contribute?
If you've built a site with Drupal, you can find a way to contribute. Documentation of issues, testing patches, writing issue descriptions, and more are all valid ways to contribute to the success of Drupal 8.
If you want to get set up ahead of time, check the thread on the Meetup page with details from the Community Tools workshop from DrupalCon 2013:
The Community Tools page is a good read to understand the whole contribution process - you'll find a link on the Meetup thread linked above.