internal error message

I am working on a new site/blog. when I click on a page or post – whether to view in draft mode or view once published on the website – I get an internal error message – stating,

“Internal Server Error: The server encountered an internal error or misconfiguration and was unable to complete your request.

Please contact the server administrator, [no address given] and inform them of the time the error occurred, and anything you might have done that may have caused the error.

More information about this error may be available in the server error log.

Additionally, a 500 Internal Server Error error was encountered while trying to use an ErrorDocument to handle the request.”

This seemed to start happening once my domain name was formally connected to the blog.

Thanks for any ideas.