Here is a presentation on Google's Core Technologies, by Google Engineer Jeff Dean. You can see at the University of Washington Computer Science web site, or at UWTV.

It covers various things such as:

• Hardware (Google Clusters), and Datacenters
• Google File System (GFS)
• MapReduce
• Word clustering
• Google News

It also has a brief overview of:

• AdSense for Content
• Google Desktop Search
• Google Print
• Gmail
• Engineering organization overview

Also, Google's keep an Open Source repository for the tools they develop and use, called Google Code.

Google White Papers

• Whitepaper on GFS.
• Whitepaper on MapReduce.

News coverage

• Internet News: Peeking at Google.
• Information Week: A Glimpse of Google.
• News.com.com: Google's Secret of Success: Dealing with Failure.
• CNet article: Good bye, Computer! Hello, World.
• Fortune and the Globe and Mail have an article on Google's Impact on the World.
• Slashdot article on technology, and another, and yet another.