If you're looking to join a team, or looking for someone to join your team, this is a good place to start.
Write a bit about yourself, such as what school you go to (MIT or not), your experience, or anything. Be careful about including contact information.
To respond privately, click on someone's username and click "message" to create a private message. You can go to your inbox at any time by clicking on your icon in the top right corner of the screen, and then clicking the envelope icon.