Deep Web Research

The Deep Web covers somewhere in the vicinity of 600 billion pages of information located through the world wide web in various files and formats that the current search engines on the Internet either cannot find or have difficulty accessing. The current search engines find about 8 billion pages at the present time of this writing. --Marcus P. Zillman

LLRX.com (the excellent law blog) has posted an article by Marcus Zillman on deep web research which includes an exhaustive list of links on searching the deep web. If you're new to the concept of searching the deep web (a.k.a. the invisible web), I recommend the section of Zillman's paper on Presentations, which lists eight different introductory, online presentations.