Problem solving in Haskell
At the University of Kent we have recently tried to incorporate more explict advice about problem solving strategies into our programming teaching. You can obtain two of the handouts we have produced from here.
How To Program It discusses general strategies for writing small-scale programs. It is based on Polya's How To Solve it.
Programming It In Haskell shows how these ideas are used in writing small to medium-size Haskell programs.
Working through an example: the palindrome problem: a larger-scale case study.
The papers are also available in PDF form and their format is rather better than the HTML versions.
A paper on A problem solving approach in teaching functional programming, published in the proceedings of the First International Conference on Declarative Programming Languages in Education .