Haskell is a relatively difficult language to try. Introductions and books almost seem to expect you to understand the syntax when you begin. And I/O is introduced late, which makes it hard to play around with.
Learn You a Haskell is an excellent introductory text and I see no way in which it "expect[s] you to understand the syntax when you begin." It walks you through things very explicitly. Yes, IO is introduced late, but it is not necessary for playing around with the language. IO is only necessary for play in languages that don't have a REPL.
I think you are forgetting that everyone who uses haskell has obviously gone through the trying it stage. It is not that hard, I did it. I just had a couple of PHP programmers do it without any problems. LYAH assumes you know very little, and explains things very simply. It gets to IO plenty quick enough, and before that it is showing you how to play around in ghci where you don't need to care about IO.