Sources

My NLP tutorial pages introduce NLP
http://www.scism.lsbu.ac.uk/inmandw/tutorials/nlp/index.html
The AAAI web site has lots of references
http://www.aaai.org/AITopics/pmwiki/pmwiki.php/AITopics/NaturalLanguage
Tokushima University - an excellent resource that makes the rest of this section redundant! It covers Information Retrieval Links , Associations / Networks / Research Cooperations , Projects , General Information & Links , Web IR & IE , Survey of Information Retrieval , Latent Semantic Indexing , Text Summarisation , Online Proceedings and Papers , Books , Lectures, Courses and many others.
http://www-a2k.is.tokushima-u.ac.jp/member/kita/NLP/IR.html
A whole book on the web! INFORMATION RETRIEVAL kindly provided by C. J. van RIJSBERGEN. It is old but covers the basics, and is still very current. We will use it extensively.
http://www.dcs.gla.ac.uk/Keith/Preface.html