Search Theory & White Papers.
Publicly available white papers, best practices, theories and publications about search related topics.
http://labs.google.com/papers/ Google Research Publications.
IBM Clever Project Dozens of great papers on search processing, link mapping, intelligent spidering processes.
DiscoWeb Applying link analysis to the web. Disco{{`Web is what became of Web}}`Spider and eventually the likes of Alta Vista & Teoma
Hilltop Search Engine based on expert Documents.
IR Theory book online This is a forthcoming book to be published on Information Retrieval theory.
Google This is the original Google paper by Sergey Brin and Larry Page
Recommended Books: