For graduating HS seniors going into CS, Google offers the CSSI summer institute in many offices, including Chicago. During the school year, they run Code-In for participating in open source projects. They are also piloting CS Edge in our larger offices. Google also has online courses and activities as well.
Here is a list of activities:
Do yourself a favor and follow Google Students and Google Education twitter, youtube, facebook, and G+ channels to see announcements for applications, deadlines, and more.