Here are some helpful resources to get you started with your LinkedIn presence:
10 Tips for Students & New Grads on LinkedIn
Why College Freshman Need to Major in LinkedIn
http://www.lothery.com/2013/06/3-biggest-networking-mistakes/
http://www.fastcompany.com/3004484/problem-your-elevator-pitch-and-how-fix-it
http://www.careerealism.com/elevator-speech-tips/
http://www.quintcareers.com/job-search_elevator_speech.html