After you've generated some keywords you can start searching for resources. There are some things to keep in mind about any results you get back from searches. We need to ask several questions of any resource before we are ready to use it to back up a point. Who wrote it? Where did they get that information? What are they trying to get do with it? Are they trying to sway you to a certain belief? Who are they targeting?
The infographic below on the acronym CRAAP can help you to evaluate sources you find online.
To go beyond evaluating the website URL ending use this checklist of criteria: