[neutralino]

I noticed this paper this morning, whilst looking through the arxiv, and thought it may be useful to some people. It's rather technical, but the introduction and conclusion should be accessible to all. Here's the abstract:

It is hoped that these lectures will give a point of entry into that vast web of related ideas that go under the name "string theory". I start with a more or less qualitative introduction to gravity as a field theory and sketch how one might try to quantize it. Quantizing gravity using the usual techniques of field theory will turn out to be unsuccessful, and that will be a motivation for trying an indirect approach: string theory. I present bosonic string theory, quantize the closed string in the light cone gauge and show that one of the states in the closed string Hilbert space can be interpreted as a graviton. I will end with some general qualitative ideas on slightly more advanced topics.