It is okay to start looking for information using Google (or internet search engine of your choice). However, using Google Scholar can help you target more scholarly information. An added benefit to using Google Scholar is that it provides links to full text articles provided by the Purdue Libraries.
If you are off campus, you can edit the Library Links in Scholar Preferences so Google Scholar will continue to highlight the full text that is available through the Purdue Libraries.
If you are expected to do a comprehensive literature search, you should consider using some of the scholarly databases provided by the Purdue Libraries.
In general, there is nothing wrong with using information you find on the Internet. However, if you do not take the time to evaluate a web site and understand who has created it, for what purpose, and where their "facts" come from, you might run into trouble. Here are some things you need to be able to talk about if we challenge your use of a particular web site: