We started at Saint Jean and scoped out the route the night before leaving - good thing, too, as there was a thick fog the next morning!
First day:
https://charitywalking.wordpress.com/2014/05/06/5-may-st-jean-to-helette/ This gives some info on us getting lost. We were using a googletranslation of this site:
http://vppyr.free.fr/pages_transversales/voie_nive/vnive.php?etp=accueil With all the mentions of farm names we had expected to see signs on gates - but there was no such thing and I have no idea how one is supposed to follow the directions to this day!
We stayed in Helette - the lady in the shop took us to the town hall to get the key. A man walked us across the square, opened the building, gave us the key and said "Voila!" That was all we needed! Very comfortable, wooden bunks, hot showers, full kitchen.
Second day:
https://charitywalking.wordpress.com/2014/05/07/6-may-helette-to-espelette/
Markers simply disappeared today and we ended up on a main road. Deciding this was definitely wrong, we backtracked UPHILL, went to a farmhouse and asked the lady to show us where we were on our map but she couldn't (checking on googlemaps later, we would discover we were only 100m away from where we needed to be!). She was very unimpressed at us not speaking French! Very. We never found the trail, but ended up back (via a different route!) back on the main road and we flagged down a German motorhomer! He showed us exactly where we were and we elected to stick to the road and forget about the trail. We had been going to head for Cambo-les-bains and then sidetrack to Espelette where there is a very comfortable albergue and lots of shops for food. We did end up there, but not via the route we had wanted to take.
Third day:
https://charitywalking.wordpress.com/2014/05/07/7-may-espelette-to-bayonne/
Because of our difficulty on the first two days, we had decided to scout out the road heading back to Cambo-les-bains in the evening. It was really dangerous with big trucks and no shoulder at all. So, in consultation with the map, we changed plans and decided to take part of the GR8 trail towards Ustaritz and it was absolutely delightful. Additionally it was very well sign-posted. There were blazes so often you could not get lost if you tried! At one point the trail joins with La Voie de la Nive and comparing the signage was fascinating - hardly any of the blue Voie markers, and those that were around were fairly dilapidated. Crisp red and white for the GR. There's a picture on that blog post to show you.
Because we had walked further than anticipated as we took the GR8 (already 25km at Ustaritz), we decided to take a bus the remaining 14km to Bayonne where we had arranged to stay with a pilgrim-friendly couple that night - I was walking with kids and did not want to push them too far too fast. Later in our trip we would have walked it easily, especially as it was flat. But we were about to walk back the same way the next day as we were then switching to the Camino Baztanes which shared that part of the path, so we didn't miss out.
Even on the perfectly flat can't-possibly-get-lost walk along the river we managed to have a hiccup. Part of the path was closed and we had to follow a detour....except that the detour signs ran out and we found ourselves walking beside a motorway. Instinct told me to take the first turnoff and eventually we found our way back to the path, but it was NOT fully marked. Asking personnel in a hotel by the motorway shed no light on our situation, asking a farmer a bit later did and he confirmed we had made the right decision and would eventually come to the river again. I imagine this has all been cleared up now!
Recommendations: stay with Katharina in Bayonne and do visit the cathedral.
Espelette is a very sweet village and has great facilities if you don't mind wandering off the "official" route (signposted as Camino Baztanes) - you could even taxi from Cambo and back in the morning. The town hall takes reservations if you want to reserve a place but do have a couple of rooms with plenty of beds.
Helette is also a great place to stay, albergue-wise as mentioned above.
The French couple I met had an official guide so that might be useful if you can find it.
I'd happily walk this route again, so please don't take my lostness-episodes as too negative!