Anything with "quick" and "easy" in the title automatically discredits itself. Language learning can be a lot of fun, but it's on a par with learning to play a musical instrument, or build furniture. You're going to spend a long time on it, and you're going to spend a long time sucking at it.

I'd second the recommendation for Farber's book. It doesn't try to hide that you will need to work, but the work can be enjoyable and productive - that's the sense of the word "easy" in this context, rather than "work-free". It also recommends some techniques for memorisation and has some great anecdotes from Farber's own language-learning experiences.

What didn't you like about Farber's book?

Thanks for asking. Because I file names phonologically in my brain, I may have been confusing Farber with Fuller, mentioned in the link I posted above. I do NOT recall anything I specifically disliked about Farber's book, upon review of that link, so consider that comment withdrawn and applied to Fuller's book.