It looks like you want to help out! That's great!
As soon as you register on the site you can leave comments on existing ladders and create new ladders. The lesson authors need your help.
Use the hashtag on twitter: #DrupalLadder to announce events, share photos from events and help promote contribution.
Login to #drupal-ladder on IRC to chat with the Drupal Ladder contributors.
More about IRC: http://drupal.org/irc
On http://groups.drupal.org/drupal-ladder you can get help and mentoring to find out how to run your own Drupal Ladder sprint, either a learning sprint or an issue sprint.
You can report problems with specific lessons in the comments on each lesson.
After you leave your comment, the lesson owner will roll in your changes and delete your comment after the problem is resolved. Or, your comment will be put into the DrupalLadder Issue queue to be assigned and completed.
The entire DrupalLadder site is available for download with the entire application, code and lesson content. If you find a problem with site content or functionality, you can file it as an issue within the project itself. The DrupalLadder distribution project page: http://drupal.org/project/drupalladder
On the issue queue for the distribution you can: