These are the official specifications, mostly by the W3C, for RDF and the technologies built on it. The specifications aren't usually a good way to start from the beginning, but they serve as the definitive references.

Core RDF Specs

The W3C Semantic Web Specifications include (all as of February 10, 2004):

• RDF/XML Syntax Specification (Revised)
• RDF Primer
• Resource Description Framework (RDF): Concepts and Abstract Syntax
• RDF Semantics
• RDF Test Cases

Besides RDF/XML, there are also these additional (and recommended) "serialization formats" in plain text:

• N-Triples: A plain text format for encoding RDF. Very straight-forward but very verbose. A subset of Notation 3, so fully compatible with Notation 3.
• Turtle: Terse RDF Triple Language, an extension of N-Triples and a subset of Notation 3 (especially recommended).
• Notation 3: A compact and readable alternative to RDF's XML syntax. (Also see: primer and rough guide)

RDF Semantics: RDFS and OWL

The W3C Semantic Web Specifications include (all as of February 10, 2004):

• RDF Vocabulary Description Language 1.0: RDF Schema
• Web Ontology Language (OWL):
  Use Cases and Requirements | Reference | Semantics and Abstract Syntax | OWL Web Ontology Language Overview | OWL Web Ontology Language Test Cases | OWL Web Ontology Language Guide

Querying RDF Data Sources

• SPARQL Query Language for RDF (June 14, 2007)
  • XML result format
  • WSDL protocol
  • FAQ (unofficial)

Publishing Best Practices

• How to Publish Linked Data on the Web
• Semantic Web Crawling: A Sitemap Extension