Hi, Katia,
I have walked from Lisbon to Porto and from Porto to Santiago, so I can only comment on those two parts. But first a couple of references for you.
-- a general guide in Portuguese, which handles Lisbon to Santiago,http://www.amigosdelcamino.com/web/caminos/presen.php?idi=C&fot=camino&cod=2
This was written by the Asociacion Galega de Amigos del
Camino de Santiago and was very helpful to me.
-- The British Confraternity of St. James has online guides to the Caminho Portugues, one dealing with Lisbon to Porto (and written by me, so maybe I'm not a good judge of how good it is), and the other for Porto-Lisbon written by Johnnie Walker, another active member of this forum. You can find them here:
http://www.csj.org.uk/guides-online.htm. I just put together a page or two of updates that people sent me after walking, and the updates are also available there.
-- My Lisbon to Porto pictures are here:
http://picasaweb.google.com/laurie.reyn ... Dxipep3Vo#
I thought it was a very pretty walk, but there are a few drawbacks:
== from Lisbon to Porto is nearly all on asphalt. Rarely on busy roads,but it's on pavement. That's hard on the feet.
== from Lisbon to Porto there are VERY few peregrinos. I met none, and most of the people I have communicated with met either none or one or two others during the entire walk. But I walked alone and never felt threatened or nervous, it is a very safe walk.
==There are no albergues south of Porto, so you will have to stay in private accommodations, or sleep in the Bombeiros Voluntarios (the guides list the towns where they are). A room in a pensao or residencial in these small towns can usually be found for under 25 euros.
Hope this gets you started in your thinking. Bom caminho, Laurie