Google is a search engine, and many times you will need to cite the article that you find on Google, not Google itself. Some of those citations are found at the bottom of the article. In order to give you an accurate way to document, I would need to know what you are documenting.
However, if you will go to Google and look up "The Chicago Manual" and then scan down to "websites" you will find some models for documenting electronic sources. You may also look up "Columbia online style". This site will give you the MLA, APA, and Chicago versions on how to site an internet source. There are differences in these styles so you will need to know which one your instructor prefers.