I'm surprised Hal's tutorial is so less known. I recommend (and send) it
to everybody who asks me.
I like that it starts early with some IO and mainly promotes ghc/ghci.
Hugs is a good tool as well (and I sometimes use it, too), but ghc is
definitively the flagship with better error reporting, active
maintainance and for producing fast code (if that is important).
It's good that this tutorial is freely available, but some people prefer
to have a proper textbook.
Maybe it is hard to recommend a single tutorial without spoiling selling
chances of others. In our teaching courses "Simon Thompson: Haskell: The
Craft of Functional Programming," is mostly used. Others find "Paul
Hudak: The Haskell School of Expression" the best.
I just see that the recent tutorial version contains Parsec (good) and
FiniteMap (deprecated) examples. I would appreciate the chapter
"Advanced Techniques" being filled (but know how much time that would cost).