Guidelines for evaluating websites.
In Google, you can limit your searches to specific websites, or you can focus your search efforts on specific types of websites
To limit results to a specific website: [search terms site:apa.org]
Example [Obesity site:apa.org]
To limit results to government websites: [search terms site:.gov]
Example [Arthritis site:.gov]
Google also has an Advanced Search page that you can use to exercise more control over your searches.