Today we had discussed on the opensuse-project List about Copyright and Licenses. So i try to clear this a little bit.
Wikipedia says: "Copyright is a set of exclusive rights granted by the law of a jurisdiction to the author or creator of an original work, including the right to copy, distribute and adapt the work. Exceptions and limitations to these rights strive to balance the public interest in the wide distribution of the material produced and to encourage creativity. Exceptions include fair dealing and fair use, and such use does not require the permission of the copyright owner. All other uses require permission and copyright owners can license or permanently transfer or assign their exclusive rights to others."
So we see: Every author or creator of any Document (like a Blog) is automaticly the Copyright Holder. The Copyright Holder can give special permissions for others who using their work.
Well known free Licenses are the Creative Commons or the GFDL. The GNU General Public License, originally written by Richard Stallman, was the first copyleft license to see extensive use, and continues to dominate the licensing of copylefted software. Creative Commons, a non-profit organization founded by Lawrence Lessig, provides a similar license called ShareAlike.
The Copyright Holder can set one of these licenses to his work. In case of CC-BY-SA all other ppl have now the permission to redistribute the stuff. A little Document in Wikipedia explains the difference between CC and GFDL.
For CC there is a great Site who gives an little HowTo for integrating the CC into a Blog.
For GFDL is there a little HowTo.