Descartes' "Discourse on Method"

It has been a while since I read any philosophy...so I made use of my friendly local library and picked up Descartes "Discourse on Method." I could not remember how the "cogito" argument went on. So here is the only way I can describe it, while not leaving too much out:

The argument for one's existence (The "Cogito" argument)
1. Even if we assume that there is a deceiver (look up Evil Demon argument), from the very fact that I am deceived it follows that I exist.
2. In general it will follow from any state of thinking (e.g., imagining, sensing, feeling, reasoning) that I exist. While I can be deceived about the objective content of any thought, I cannot be deceived about the fact that I exist and that I seem to perceive objects with certain characteristics. (The famous statement of this from D.'s Discourse on Method is "Cogito ergo sum." or "I think, therefore I am.")
3. Since I only can be certain of the existence of myself insofar as I am thinking, I have knowledge of my existence only as a thinking thing (res cogitans).
This shows that the contents of the mind are more easily known than the body. Which is a whole other argument.