Introduction to Parallel Computing
taped2thedesk writes "The University of Michigan Center for Advanced Computing recently conducted a introductory workshop on parallel (cluster and grid) computing systems. They posted all of the presentations and notes from their workshop online.
I attended the workshop and found it very informative - code examples are in C and Fortran, but programmers of any language can understand the concepts they present." (Note: requires a program that can display powerpoint slides.)
gridMathematica also runs in parallel for those who need to process extremely complicated mathematical forms.