Information Retrieval (study) resources

If you're looking for a way of getting to know the background of IR, there's a plethora of options (online) available. From the classic book by Keith van Rijsbergen (1979), the upcoming IR book by Manning and Schuetze (who previously wrote the classic "Foundations of Statistical Natural Language Processing") to various lecture pages of IR courses taught around the world. For example, David Carmel's course page at Haifa, James Allen's course page at UMass, Jamie Callan's course page at CMU, or ofcourse the course taught by Maarten de Rijke (which is more general and centered around "internet information").