I know these resources have been mentioned before on Dharma Overground, but I wanted to make sure that everyone - especially anyone new to this site - is aware that books by masters of insight meditation are available for free on google books.

Some are available in full text, others in partial form. I've selected a few of my favorites for easy access below:

In This Very Life:
http://tiny.cc/Iria5

Practical Insight Meditation:
http://tiny.cc/qLJvr

A Still Forest Pool:
http://tiny.cc/CIs1R

Modern Buddhist Masters:
http://tiny.cc/447Ts

A note about the last title: To save you the trouble of trying to find them, I'll mention that almost none of these masters are living any longer. However, I believe disciples of every one of them can be found around the globe, some easier to study with than others.