The basic information is pretty well summarized here http://www.rdfabout.com/ Automatically mapping disparate data sets is a pretty hard problem that does not tend to automate well. My current company produces tools for this and you can download a beta here http://www.topquadrant.com/products/TB_Composer.html The basic technique is to import your datasets (XML files or RDB or whatever) into RDF, then define a master data model in RDF and define a set of sparql construct rules (or SPIN rules, spin is one of TQ's proprietary languages) which says what I see data with structure X in data source A construct structure Y in data source A using the fields of X. The chief scientist at TQ has written a book on how to effectively do modeling with RDF : http://workingontologist.org/ There are a number of other books and tools, you can checkout the semantic technologies conference for exhibitors for a full list.