For Google search you must memorize the word(s) (since there is no "Copy" for selected text), then: Menu>Home (yes, you must exit the book you're reading)>Menu>Experimental browser>type in google.com> type in word(s) if you still remember it/them

And I
think, ( never owned 3G Kindle model

) you can't use 3G for that, you must use WiFi.