Introduction to Superstring Theory
  These four lectures, addressed to an audience of graduate students in experimental high energy physics, survey some of the basic concepts in string theory. The purpose is to convey a general sense of what string theory is and what it has achieved. Since the characteristic scale of string theory is expected to be close to the Planck scale, the structure of strings probably cannot be probed directly in accelerator experiments. The most accessible experimental implication of superstring theory is supersymmetry at or below the TeV scale. 
John H. Schwarz