[I've had to split this into a number of posts as I can only include two links per post]
I have been looking into the resources available for learning Portuguese and thought I'd summarise what I've found so far:
Brazilian or European Portuguese?
There is far more available for learning Brazilian Portuguese than European Portuguese. I am in two minds about whether to start by learning Brazilian Portuguese. As far as I can tell, the major differences are in pronunciation, some grammar, and some words. I'm wondering whether the differences are comparable to the differences between North and South Welsh in that it would be obvious to a native speaker which you are speaking, but they would still be able to understand you.
In terms of pronunciation, it seems that Brazilians pronounce vowel sounds a little more clearly than Europeans, so that might make it easier to learn, but then it might make it harder to understand European Portuguese when you go to Portugal, which is my aim at least (although I wouldn't be averse to a trip to Brazil...).
In terms of grammar, the biggest difference I've encountered so far is that Brazilians very rarely use 'tu' for you whereas this is widely used as the informal form of you in Portugal. Instead, Brazilians use 'você' widely, whereas I have read in many places that this is considered rude in Portugal. There is a quite a lot of conflicting advice about this, but I think what Portuguese people do is just miss out the word você, so it might not be too hard to adjust to this if you've learned Brazilian Portuguese.
European Portuguese resources
This blog is quite useful and is primarily focused on European Portuguese - http://www.learningportuguese.co.uk/
This is a good list of resources available -