When developing a website, it's important to be aware of the competition.  How are they attracting visitors?  What do you like or dislike about their sites? 

 Marketleap

The Marketleap search engine tool compares the volumes of links to your site with the volumes of links to the leading sites in more than 30 industry categories. 

 Alexa

Alexa is a great tool to identify and learn about your competition.  Simply type in the URL of a site and see how it ranks!