There are approximately zillions of specialized search engines out there, as can be seen at Search Engine Guide. The list below is a selective subset of these, chosen because they might help you find materials useful as resources in a WebQuest. All of these links lead to sites that contain specific information that may not turn up when you do a general search of the Web using Altavista, Yahoo, and other search engines and directories. For a more comprehensive list, you might also want to check the Invisible-Web site.
A PDF of his presentation. Relatively basic but has some nice introductory slides that would be helpful to someone who had no experience with PBL or webquests or online projects.
Young students are encouraged to use web based learning and WebQuests are a great way to introduce them to this. Combining literature with computer research encourages even the most reluctant of learners!