Earlier today I learned from Kristen Swanson about a new video explaining how web search works. This video, produced by Google, features Google Search Engineer Matt Cutts explaining what happens when you do a web search on Google. Cutts also explains how Google indexes and ranks websites. The video is embedded below.

Applications for Education
Despite a little bit of Google propaganda at the end, this video could be quite useful for helping students understand what happens when they do a Google search.

Here are some related items that may be of interest to you:
Collecta, Real-time Search, and Professional Learning
Real-Time Search Options
Lesson Plans for Teaching Web Search Strategies