Hi, Jesse, and welcome to the forum!
There is a pretty solid group of people who have walked from Lisbon, are active forum members, and have lots of information to share, including magwood, almorfati, diogo, amsimoes, albertinho, Stephen Nichols, MichaelSG, and undoubtedly more I've forgotten.
I'm sure you will have tons of questions, but I can also point you to some resources that should help you.
For starters, check out Maggie's blog,
http://magwood.me/camino-portuguese/ It will give you a real sense of what the Caminho from Lisbon is all about.
There are also a couple of resources in the resources section of this forum.
A short guide from Lisbon to Porto:
https://www.caminodesantiago.me/community/resources/the-caminho-portugués-–-lisbon-to-oporto.123/
A short guide from Porto to Santiago:
https://www.caminodesantiago.me/community/resources/the-camino-portugués-–-oporto-to-santiago.124/
A document that helps you figure out how to cut some of the longer stages, if you are not inclined to walk 30+:
https://www.caminodesantiago.me/community/resources/short-stages-from-lisbon-to-porto.133/
I am handling revisions to these documents and hope to have updated versions by early 2015. But they are a good start.
I would also recommend the ViaLusitana's website. They are the Portuguese Caminho group that has really promoted the walk from Lisbon and taken it out of obscurity. They have the most up to date listing of albergues,
http://www.vialusitana.org/en/albergues_eng/, but if you are only interested in private lodging you will need to find more information -- the online guides have a lot, as does
John Brierley's hard copy guide (at least I've been told that, I have actually never seen his guide).
And I would also peruse the many posts in this section of the forum, because you will find a lot of interesting and helpful comments and suggestions by the people I've mentioned above, and others of course.
As far as luggage transfers, it will require some careful planning. Mario of Santarem Hostel and other owners of properties south of Porto have a service in connection with their lodging offerings. A taxi is always an option, and the charges tend to be about 1 euro a km, so that could be kind of steep. Once in Spain, it's easy. See this recent thread:
https://www.caminodesantiago.me/com...portugues-between-valenca-and-santiago.30082/
Anyway, I'm sure this is a bit overwhelming, so I'll stop now and just say that you should feel free to ask your questions because we are a pretty friendly group here, very opinionated on certain things perhaps, but very friendly.
Bom caminho, Laurie