How do I perform a Mail Merge in Word?

While Works' proprietary native WKS (spreadsheet), WDB (database) and WPS (word processor) formats limit its utility for large(r) organizations, the simplicity and ease of integrating database/spreadsheet data into word-processor documents (e.g., mail merge) have made it a favorite of small and home-based business owners. Version 4.5a is particularly noted in this respect. The database, while a "flat file", I.E. non-relational, allows the novice user to perform complex transformations through formulas (which use standard algebraic syntax and can be self-referential) and user-defined reports which can be copied as text to the clipboard.