Free Book: Introduction to Metadata
This revised edition of Introduction to Metadata, first published in 1998 and updated in an online version in 2000, provides an overview of metadata—its types, roles, and characteristics; a discussion of metadata as it relates to Web resources; a description of methods, tools, standards, and protocols for publishing and disseminating digital collections; and a handy glossary.
Free Book The Unicode Standard Version 5.0

The Unicode Standard, Version 5.0 is available as a free download. Each chapter can be downloaded in pdf format.
Version 5.0.0 of the Unicode Standard consists of the publication The Unicode Standard, Version 5.0 plus the Unicode Character Database, Version 5.0.0. The book gives the general principles, requirements for conformance, and guidelines for implementers, followed by character code charts and names and the text of all of the Unicode Standard Annexes.