The canonical tutorial paper is in the Advanced Functional Programming Summer Schools series:

C. Runciman and N. Ro"jemo. Heap profiling for space efficiency. In J. Launchbury, E. Meijer, and T. Sheard, editors, 2nd Intl. School on Advanced Functional Programming, pages 159-183, Olympia, WA, August 1996. Springer LNCS Vol. 1129.

Great! I knew only the more compiler-oriented Runciman/Röjemo papers. (Which were already helpful, but not very 'tutorial'.) Thanks, Markus