Hello,
I did the Camino Portuguese starting from Porto in August. You can get your credencial at the information desk in the Cathedral (where you would pay to get entry to the cloister). You need to pay a small fee for the credencial (50 cents, I think). You enter the Cathedral via the large door that faces the plaza that gives you a view of the river. On the opposite side of the plaza from the main door and a bit to the right, you will see a stone ramp/stairs going down hill. You will pick up the first marker here. The cathedral does not provide you with any information about the route. I used the
Brierley guidebook to the Camino Portugues (available from amazon). It is excellent as it has good descriptions, maps of the route within larger cities and towns, info on accomodation, easy to read maps of the route, topographical advice, etc. The way marking in Portugal is very good indeed. The marking out of the city of Porto is also good. However, there are a few places where you could go astray if you didn't have a map which helped you know where to look for way marks. In Spain, particularly between Tui and Ponte de Lima, the waymarking could be a lot better. Here a guide book definately helps. The CSJ website has a downloadable guide (see link above just below the map). It is free to download, but they do ask for a donation. I haven't used their
Camino Portugues guide, but are ususally quite detailed. However, they don't have maps and topos. Check out the mundicamino website for this. Still, I would go with
Brierley if you can get it shipped to you in time. Check out my 'live from the camino'. I mention the areas where the way marking is problematic. Leaving Tui is particularly challenging.