I recently helped pull together (and write an article for) a special issue of A List Apart dedicated to site search analytics. ALA is a fantastic publication that's moving from covering web design to focusing on user experience, and I'm grateful that they were willing to devote an entire issue to SSA.

Avinash Kaushik of Web Analytics: An Hour a Day fame takes a Web Analytics-based approach to the topic in his article, "Internal Site Search Analysis: Simple, Effective, Life Altering!". My article, "Beyond Goals: Site Search Analytics from the Bottom Up," is written from a UX perspective. And tying these threads together is John Ferrara with an excellent case study, "Testing Search for Relevancy and Precision," based on his work at Vanguard.