Painless Vim by Nate Dickson is a new book about Vim, with a lighthearted tone yet well-researched content. It's published on Leanpub with no DRM, and the minimum price is $5.99. There's a free chapter so you can try it first, and a table of contents so you can see the planned content:
Painless Vim is written by a professional developer who tried to learn vim a number of times before it finally stuck. I kept falling into the same cycle: I'd read a wide a array of books, online tutorials, print-outs, go through all their steps, and in the end get almost nowhere. Then I'd quietly go back to my editor of choice until next time I decided to try it out.
The author describes the book as beta right now, so there's still work left to do on the prose and technical accuracy:
Painless Vim is in beta status, meaning it's still being actively revised, and a lot of the text is in a rough-and-ready first draft state. At this point the text is undergoing fact checking, the code samples and exercises are going through testing, and all kinds of grammatical and stylistic clean-up things are happening.