This doc sprint is timed to coincide with and support the various Sprint Weekend events (http://groups.drupal.org/node/277768) which are taking place on March 9 and 10. This will allow attendees at any of those local events to also be a part of a global doc sprint.
There's plenty of work to be done, including general activity on the issue queue:
https://drupal.org/project/issues/documentation
Getting started on the Drupal 8 docs:
https://drupal.org/project/issues/search/documentation?issue_tags=d8docs
Or performing the heroic work of cleaning up comments:
http://drupal.org/documentation/manage?order=comment_count&sort=desc&com...
Communication will take place on the #drupal-docs IRC channel. I'll be on IRC from 9 to noon on Saturday and all day Sunday (Eastern Time in North America) to discuss problems and answer questions but if you have a problem outside those times please feel free to email me through my contact page and I'll do my best to get back to you.
For general information on how to contribute to documentation, see https://drupal.org/contribute/documentation.