A good old-fashioned paper map might be a good starting point.
You can order the 'Michelin Road Atlas: Cemeteries and Memorials in Belgium and Northern France' for just £7 (inc postage) from the CWGC:
http://www.cwgc.org/c...20for%20Sale&menu=sub
Once you'd planned a general route you could then (if you required more detailed maps for cycling) obtain the relevant 'IGN Top 100' maps from Stanfords (which is the world's leading supplier of maps - and my favourite shop in London!):
http://www.stanfords....-Verte_SI00000297.htm
Chris