As explained on The Internet: Ideas, Activities and Resources:

The Internet can be a researcher's dream come true. By browsing the Internet, much as you would browse the shelves of a library, you can access information on seemingly limitless topics. In addition, web-based catalogs are available in many libraries to assist researchers in locating printed books, journals, government documents, and other materials.

Possibly the biggest obstacle facing researchers on the Internet is how to effectively and efficiently access the vast amount of information available with the simple click of the mouse. With the Internet's potential as a research tool, teachers must instruct and guide their students on manageable strategies for sorting through the abundance of information. The search for reliable resources can be both overwhelming and frustrating if students are left on their own in their initial search. A few simple guidelines can make conducting research more manageable, reliable, and fun.

For detailed guidelines on the effective use of the Internet as a research tool, see: http://fcit.usf.edu/internet/chap5/chap5.htm