While surfing today I found an entire chaper from "MDX Solutions: With Microsoft SQL Server Analysis Services" available online.
Chapter 4: Advanced MDX Application Topics – http://media.wiley.com/product_data/excerpt/67/04714004/0471400467.pdf
It’s from the 2001 printing; there is a 2006 edition out and I highly suggest purchasing it.
The 2006 edition also has an entire chapter available.
Chapter 6: Sorting and Ranking in MDX – http://media.wiley.com/product_data/excerpt/80/04717480/0471748080.pdf
Jesse Orosz: SQL Server Analysis Services Blog 