In reply to Enty:
there's basically only one guidebook...they made the new edition lately and some people like it some don't...it is made with pictures of the huge wall instead of drawings, and some people find the pics confusing...
still it's worth getting it because it mentions all the exact rappel lenghts, in all the possible combinations...
then there's this topo made by those who sell online pdf topos. Think you can easily emule it (?forgot the name?)
very practical for bringing in your pocket while climbing but very very poor in information, you need to fill in your a4 sheet with additional notes...taken from the good topo!!!
anyway, the bar at la palud always have a topo (maybe not the most updated edition) you can look at : in desperate cases, you copy the stuff you are interested in by hand..
and you should be able to buy a new-edition one on the spot.