It is my understanding that deGaulle is the only international airport so you
don't make the choice. I don't recall if there were signs in English but we
didn't have any trouble finding customs, then our luggage and then a phone
to call the shuttle we had reserved. I do understand your reluctance though.
I would certainly recommend you use the shuttle. We found the metro and
buses easy to use, but I would not have wanted to do it with luggage and
after a flight from the west coast especially. I am returning with my
daughter in April and am marking the map and searching the web for those
special places we missed the first time. Make sure you leave time to stroll
a market or two and to just walk your neighborhood. And watch as many PBS
travel specials as you can - it does give you some feeling of familiarity
when you see the real thing.