Hello Lebanese Pilgrim!
I have never bought or possessed a guide book, because living in Costa Rica, nothing is available here. I use various web sites, such as mundicamino.com , caminodesantiago.consumer.es and godesalco.com Up until last year, the most practical one, at least for me, was the caminodesantiago.consumer.es, as you can print out your version, however this year, they have greatly expanded it and it's becomming far too much to print out to be practical. This year, I will take my 2009 version with me (with all my additions that I add). Godesalco is good for the list of villages and towns you will pass through and gives distances between each place. The other two have a bit of everything, including information of the day's walk, what you should look out for as regarding interesting churches and monuments, etc. caminodesantiago.consumer.es is only in Spanish, mundicamino is in several languages (you hit on the flag of your desired language at the top the page. Added to that, you can't go very wrong: there are yellow arrows everywhere, unless you take a less used trail, which happened to us a few years ago walking from Samos to Sarria.There will also be loads of people walking by the end of June, so just follow the crowd! When you get to bigger villages and towns, you might pick up some information regarding the surroundings at the local information centre.
For your Pilgrim passport, I think that you could also go to the main albergue in Pamplona the next morning and they should be able to issue one. Buen camino, Anne