Pfui - 6:49 pm on Jul 20, 2011 (gmt 0)
Then, after your robots.txt and sitemap file and meta tags are good to go, use Google Webmaster Tools to confirm everything. And then remove a directory whole-hog from Googlebot's reach:
-> Site configuration
--> Crawler access (where you can test robots.txt)
---> Remove URL
See also the following page linked-to from "Crawler access": "Do I need to make changes to content I want removed from Google?"