On the Mac, simply type...
option-[ for “ (left curly quotes, in case it doesn't show up correctly on this forum)
and
shift-option-[ for ” (right curly quotes)
For windows...I haven't a clue, but I seem to remember there are some arcane codes you can type to achieve the same thing.
Cheers,
Tony
NB: This works on a British keyboard, I think it should work on others.