I just noticed this post on the freebase dev blog - announcing the release of a new book about "programming the semantic web" written by freebasers Toby Segaran, Colin Evans, and Jamie Taylor. I haven't picked it up yet, but based on the description there and in the amazon reviews, it looks like a(nother) nice explanation of the concepts involved in the semantic web as well as a set of practical programming examples based on the W3C standards (OWL, RDF, SPARQL, etc.).
I found it surprising that freebase was not mentioned anywhere in the brief description given in the post or on Amazon.