Typically the earliest date will be the copyright date of the original work, and the latest date will be the copyright of the particular edition you have. If the notification is not completely clear, the cataloging-in-publication information should help.
For example, I am looking at Kohn on Music Licensing, 4th edition. The notification is © 1992-2010. This would mean that the first edition came out in 1992, and the work is consistently being revised. However the CIP data for this physical book gives the Library of Congress classification as KF3035.K64 2000, which means this 4th edition book was first published in 2000. Going back to the original notification of © 1992-2010, I would expect that this particular copy was printed in 2010.
For the purposes of a bibliography, I would give the date of this 4th edition book as 2000. For the purpose of determining copyright status, the copyright and publication dates are immaterial: it will be protected for the life of the authors plus 70 years.
Because the term of protection is usually measured by the life of the author rather than the copyright date of the item, it may seem that the copyright year is unimportant. However it gives an excellent indication of the currency of the materials, and does form the base line for measuring term of protection on certain works.
Google gives the copyright date as the current year, because that's the date the page rendered.
No. But you may need to be quite careful about whether a particular piece of software is actually public domain, i.e., its copyright has expired or it never had any copyright (if published prior to 1989, or a work of the US government).
Copyright gives the creator of a work control over its use. A license is a way the copyright owner can allow others to use the work.
The copyright office only gives one address, in New Delhi.
Perhaps the most straightforward right is the right to copy. In many countries, copyright also confers a moral right, which gives the right to be identified as the creator.
A copyright gives the owner the exclusive right to reproduce, distribute, perform, display, or license original material.
Copyright protection gives creators the chance to ascribe value to (and perhaps derive income from) their creativity and hard work.
The copyright page of a book gives much more information than just the copyright. It includes the cataloging data from the country of origin, edition information, and often even the typeface and paper quality.
Websites usually give the current date as the copyright date, as that's when the page rendered on the user's computer. IMDB also gives a copyright notice at the bottom of every page, although that is not required.
Copyright law gives the creator of a work the exclusive right to copy, alter, distribute, perform, or display the work, or authorize others to do so, for a limited time.
Nearly everything, unless explicitly stated otherwise. The link below (to Project Gutenberg) gives an example of materials that would not be protected by copyright.