Place your cursor on any of the four corners. the cursor will change into a small double ended arrow, . Hold down the lefy mouse button and drag the the screen open. The system should 'remember' the next time you open Google
Just to be pedantic - do you mean maximum sized window or fullscreen browser (with toolbars hidden)?
I think other respondents here think you mean the former; if you mean the latter then I haven't come across anything that will do it on a site-by-site basis.
Right click on the start menu, quick launch, or desktop icon which you use to open IE7. Click 'Properties', then 'Shortcut' tab. In 'Run:' box select 'Maximized'.