I know there are a bunch of small guides / articles written by the author of fp-ts, but is there a good book, guide, etc. for diving in for someone who is kind of familiar with functional concepts but not quite ready for going full haskell? A book on haskell?
I've just gone through this process over the last couple of years. To be honest, the most effective learning tool for me was dedicating my free time for a little while to learning Haskell. It's a higher upfront cost but a huge pay-off, not just in terms of understanding fp-ts but more broadly in how you'll be able to view programming through a new lens.
That said, I wrote this[1] a year and a half ago for some colleagues just as I was getting into it myself. I hope it helps, and if not let me know if there's anything more specific I could help with.
Much appreciated. I'll be sure to read through the post. I did buy a haskell book (Haskell Programming From First Principles) but haven't had time to read through it. Like you said, while there's a big upfront cost, it seems to be the most effective strategy.