Paris - Gare Du Nord station layout

RER E (East-West) is almost directly below the B line (North-South), down four escalators. The transfer takes from four to five minutes.

Correct. Tons of escalators linking the two.

Thanks! The original plan was to change onto line 9 (need to go near Chausee D'Antin La Fayette or St Lazare) at Chatelet Les Halles RER station but I'm convinced that a better option is to change from RER B to E at Gare du Nord.

The answer to your first question is
www.enjoy-europe.com/hte/chap17/p1020028.htm. It is a photo and somewhat fuzzy in the detail.

I have a similar question about Gare du Nord. I'll be getting of the B line form CDG and looking for the #5 line to Place d'Italie. Does anyone know where it is & how close it is (especially with some luggage)?

I believe all the metro station entrances are off to one side of the station, so it doesn't matter which line you want, they're all together (well, different tunnels/halls to the platforms, but they all split off from the same main hall). You go past the ticket windows. It's possible the RER platforms are one level and the Metro platforms are another level (down, of course).

Try these:
http://parisbytrain.com/gare-du-nord-photos/
http://parisbytrain.com/files/2008/10/gare_du_nord_map.gif

p.s. if you are actually going TO place d'Italie, you could stay on the RER-B to Denfert Rochereau, then change to metro Line 6 (toward Nation) to get to Place d'Italie. From this RER you walk underground (walking under place Denfert Rochereau and Avenue Gen Leclerc) to the metro area...

Travelnut is right. But, if you have a lot of luggage this can be a real pain in the butt. I'd spring for the taxi -- it won't be too much especially if you get in late at night.

If the taxi appeals to you, your travel time and fare would be minimized by riding the RER to Denfert-Rochereau, then getting a cab there.

Exactly where are you going - and at what time of day?

we get in at 9am & will be heading to the 14e (Liberte metro stop). so we'd be getting off the #5 at Republique and transferring to #8, i believe.

we'll be traveling pretty light, too.