I generally like Firefox, and generally like Google. But having Google suggest enabled when I search for things is annoying, at least on my rather small laptop screen. Mostly it is because my internet right now is pretty crap, so I try to cut down on any extra traffic. Anyhow, I didn't even both Googling how to do this:
Type in 'about:config' into your address bar and type 'search' in the top filter bar. Look about half-way down for this:
Double click it to turn it to false. All done.