Excuse the stupid question, but I need to write km squared - where do I find the little '2' to say squared????

hold ALT. then type 178. then release ALT.

Alternatively, go to INSERT MENUSYMBOL and find it on the character map.

OR just type a regular 2; highlight it; go to FONT; and check the box that says superscript.

Cheers x

Failing that - hold ctrl+shift, then press '=' towards the top of the keyboard (next to backspace). This will put you in superscript mode. Do it again to go back to normal, or just hold ctrl and press '=' to go into subscript mode :)

I just recently discovered that last one, completely by accident - after years of using the menu at the top. It's much faster.