If you like to have Safari starts with a specific window size and location, put the below code in the address bar:
javascript:self.moveTo(120,75);self.resizeTo(1440,900);self.location="http://www.apple.com";
You must paste the code and hit enter, to save the window size and location, hit CTRL+T and close the old tab, this new tab must be the last one. Then close Safari (CTRL+Q) and re-open it.
My 13" MacBook Air is set to
javascript:self.moveTo(200,0);
self.resizeTo(1040,900);
self.location="http://www.apple.com";