I recently used this guide (May/June 2011) for the pilgrimage between St Jean Pied de Port and Santiago.
The guide was written in 2007 and is out of date (mainly due to a massive road building program by the Spanish); roads have been turned into motorways (which don't allow bicycles) or re-named due to the new roads.
There is a question mark on the mileages given in the guide; the author states that the mileages are plus or minus 5 km, which is unacceptable in my opinion.
The guide does not give any idea of the size of towns or villages on the route which was unhelpful.
The guide also does not include street plans of the larger towns or cities like Pamplona or Leon; all it says is find the tourist office for a local map - it actually acknowledges that the Pamplona tourist office is impossible to find (it's currently in a porta-cabin in front of the cathedral)!! Would it have been so difficult to add city street plans?
I met another couple who had the same guide and they commented on the general negative tone of the author.
I eventually did not trust this guide and treated all information with suspicion, which certainly added a bit of adventure to the pilgrimage.
The authors route descriptions could be mis-leading ie not very clearly written - which caused me one day to go 6 or 7 km in completely the wrong direction, luckily a local saw I was way off and corrected me.
I have given this guide two stars as it does give the outline of the route.