you can use the Get Pages operator to get the contents of a number of websites whose links you provide in a data table.
You can then use the text processing extension to count the words that appear in the different sites. Our websites provides some links to video tutorials for the text mining extension: http://rapid-i.com/content/view/189/212/lang,en/
To focus on the contents of the websites and remove all html tags you can use the Extract Content operator.
Finally, to execute the job regularly, you should use the RapidAnalytics server, also available on our website.