What is a good book or tutorial on Standard ML?
I like Introduction to Programming using SML, Michael R. Hansen & Hans Rischel. Its a good beginners book. For more in depth coverage I like ML for the Working Programmer, L. C. Paulson.
Some tutorials: Gentle Introduction and this
I quite enjoyed The little MLer. It doesn't focus on teaching you the SML Standard Library but instead on the usage of pattern matching, recursive types, recursion in general and program construction.
If you got no prior experience in a ML like language, it will definitely be worth the read (if you like/get used to the writing style).
If you are a C programmer, Jeff Ullman's book Elements of ML Programming provides a very smooth on-ramp, but the problem is that Ullman's ML is not at all idiomatic. In my class, he would lose lots of style points.
Paulson's book is good if a bit long-winded. It's what I recommend for people not coming straight from C.