I have known google to be so busy it seems down/time's out.

If you get no response from a site try
http://isup.me
This is a short URL for the above.

If no URL's work, test if your DNS service is down.
By keeping Google's IP in your bookmark's, currently it's
http://74.125.224.72/

Personally I use
OpenDNS for my DNS and DuckDuckGo for my search engine