Edit: for the record I have Googled the topic and am overwhelmed by how much is out there. Looking for personal recommendations.
For what it's worth, I got a surprising amount of mileage from learning Idris[0], of all things. Even if you ignore the dependent type system, it is still essentially Haskell but with a lot of the warts removed, making it much simpler to grok.
Beyond that, the usual recommendations apply: Learn You a Haskell[1], and Real World OCaml[2] were what got me started.
[0] http://docs.idris-lang.org/en/latest/
Haskell, OCaml, etc take those functional idioms and apply strong typing, algebraic data types, pattern matching and something like the Option/Maybe type - but they build on the same functional concepts in Realm of Racket.
Caveats to the above:
1) Racket has an optional 'typed' variant which gives you type checking.
2) Rust is (IMHO) a little weaker with regards to pure functional programming than OCaml, but very nicely integrates pattern matching, type checking and algebraic data types in.
If some concepts remain unclear, Learn You a Haskell[1] is a good complement, though it doesn't go as deep as Real World Haskell. For example there is no coverage of monad transformers, which is a pity.
Typeclassopedia[2] is a great overview of common category-theoretic abstractions used in Haskell programs.
[0] http://book.realworldhaskell.org/read/
In any case, that book ain't bad either. It's better than Learn You A Haskell.
I also like "Discrete Mathematics Using a Computer" (https://github.com/ryukinix/discrete-mathematics/blob/master...). It focuses on teaching discrete mathematics and introduces some Haskell as executable mathematical notation on the side.
My experience has been that, generally speaking, programmers of language [X] don't have a particularly good grasp of what makes a good introduction to language [X], and I think that effect is even stronger with a difficult language like Haskell.
That said, I was about to read some of the new material in HPfFP, and I should also read the analogous wikibook content as an experiment. Thanks for linking it.
I remember a particularly vivid example of some of my coworkers at Google suggesting the Go tutorial, starting at https://tour.golang.org/welcome/1, to someone completely new to programming. They couldn't even understand how it's not perfectly clear and simple.
That being said the book that I've seen most success with getting someone from absolutely zero to "can start making progress on their own" is "How to Design Programs" (http://www.ccs.neu.edu/home/matthias/HtDP2e/index.html). It helps that the authors regularly teach absolute beginners.
When I wanted to build something beyond a toy program, https://pragprog.com/book/vmclojeco/clojure-applied helped me immensely. It goes beyond "what you can do" and delves into "when you should do it". IMHO every language should have a book like this.
He focuses on teaching the syntax, semantics, and idiom of Standard ML, a classic functional programming language that's closely related to OCaml, Haskell, and others. He has a gift for explaining simply and clearly and keeps his lecture videos short (~10min) which helps to absorb their info. Check it out: https://www.coursera.org/learn/programming-languages