Back to Basics - about O(n) lookups and unnecessarily increasing a program's complexity by an order of n.
Five Worlds - about the differences between Shrink-wrap software, one for internal use, throwaway, embedded and games.
Note: Joel's articles are mostly relevant to commercial, market-place software, and should be taken with a grain of salt in regard to writing voluntary, open-source one. (and should be taken with a grain of salt in any case, because he seems very opinionated)
General Freecell Links
The Freecell FAQ - a comprehensive document answering many commonly asked questions about Freecell and the Microsoft Deals