NLP keyword extraction, bayes therom. Where do I start?

First of all I would like to apologise as I'm new to programing( java)

I'm working on a side project where I'm extracting "meaning" from medical records. This would involve keyword extraction and text summarization.

How would I apply bayes therom to something like this to develop a text processing technique?

I know how bayes work in a statical sence but I don't know how to apply it to text processing.

And how does a program "Learn" from bayes?