Recently, I was asked for pointers to introductory material on the Semantic Web, specifically for such topics as N3 and Turtle. I found "The Semantic Web 1-2-3" the most helpful in starting to get to grips with the mysteries of the SemWeb. Note, however, that it is somewhat outdated now (it refers to DAML+OIL for example). But it is still a good foundation and it has more links to great semwebby material than you can shake a stick at, if that's your idea of fun. A couple of extra links that might be of help are
I can't really find anything good that explains Turtle, other than the formal spec. But my twitter-length explanation is that Turtle is N3 minus the reasoning extensions but plus internationalization (i.e. it is a more exact rendition of RDF than N3 is).