The web can be a powerful tool for research, but to use it effectively, you must first know fundamental navigation skills, evaluation techniques, search strategies for search engines, the structure of URLs and more.
An excellent starting point is the Penn State Libraries Information Literacy Tutorial "Information Literacy and You", section on "Using Web Resources".
http://www.libraries.psu.edu/instruction/infolit/andyou/infoyou.htm
More detailed information can be found in the tutorial "Finding Information on the Internet", developed by the University California Berkeley Libraries.
http://www.lib.berkeley.edu/TeachingLib/Guides/Internet/FindInfo.html
Bare Bones 101
A basic internet tutorial developed by the University of South Carolina, Beaufort.
http://www.sc.edu/beaufort/library/pages/bones/bones.shtml