Now that you know the importance of giving credit to the sources you use, here are some Web sites that demonstrate the "official" form to use.

Columbia Guide to Online Style- http://www.columbia.edu/cu/cup/cgos/idx_basic.html
    This site gives forms and examples for properly citing almost anything!

ThinkQuest-Citations and References    http://www.thinkquest.org/web/citations.html
    While this guide was specifically created for the ThinkQuest competitions, it does provide an acceptable template for general school use.

Of, course there are many other pages that could be listed here, but I tried to choose those that gave examples and covered many different situations.