There are hundreds of war cemeteries along the western front. To help you find a particular cemetery or grave, underneath mentioned sites are very useful;
 
Find a grave
Here you can search on soldier's name, location and more
https://www.findagrave.com/index.html
 
All English cemeteries in France, indexed on alphabet

English cemeteries in France

German war graves commission
 
Commonwealth WW1 military cemeteries in France
 
French WW1 battles