The easiest way to start contributing to LCSK is to check the Issue Tracker tab and pick a feature or task that you want to work on.
From there you can create a fork and name it appropriately based on the feature on task. Work on it from your own repo and once you have completed the feature / task simple request a pull request.
If you changes are approved they will be added to the master branch, and you should get yourself a ticket to the Developer role.
I'm really thrilled about the new version, SignalR is really nice I most say.