Norwegian is actually a fairly obscure language when it comes down to it. There are only 5 million speakers of Norwegian in the entire world, and not a ton of demand to learn it, so that means that most language learning companies ignore Norwegian. For instance, Rosetta Stone does not currently offer a Norwegian program (though they do offer a Swedish program). No matter, there are still plenty of resources out there, it’s just a matter of finding them. I have bought 2 textbooks, a Norwegian-English dictionary, and I am using a deck of Anki flash cards. If you aren’t familiar with Anki, it’s flashcard software, which follows a supposedly researched pattern of presenting you with flashcards as soon as you were about to forget them, and does continual review. It has been fantastic for helping to increase my vocabulary, and helping it to stick. Additionally, the deck of flashcards that I have also include a native speaker saying the phrases, which allows me to hear the correct pronunciation, as well as practising hearing Norwegian. The 2 textbooks that I have are really nice as well. One of them is a textbook that came with audio CDs, which are useful for practising listening skills, and the other textbook is actually a book that explains the Norwegian grammar, in a clear, precise, English way. This has been very helpful to making my Norwegian be not just intelligible, but actually correct.
The textbook with the audio can be found here, and the grammar book can be found here. The dictionary I use is here, though I suspect that any dictionary will do just fine, and the set of flashcards that I use can be found here, and the program you need to download (anki) can be found here.
Oh, and one last super important thing, I’ve made a bunch of Norwegian friends to help me out when I have specific questions that the books don’t answer, and to have conversations with in Norwegian. That is an incredibly important part of truly learning the language!