You can, of course, read the wikipedia article to get started. I usually do, just don't use it as the only source in your paper. Use it to get your basic education.
Another interesting source can be found in the writings of Eric Flint at Baen when he writes as the Prime Palver. Especially cite-worthy is his post that shows a speech on copyright in the English parliament from the 1800's. See it here:
http://www.baen.com/library/palaver4.htm
From a globalization point of view, there are four different things that complicate all of this.
1) What exactly does a copyright cover? You can't copyright a letter "T" or a word "The". You can't even copyright a plot -- many plots are similar. On the other hand, You can't take a complete work and change one word and claim it is different. Bottom line is that what is protected is open to some interpretation. Furthermore, there is the thought of "fair use" that allows you to use some portions of a copyrighted work for specific purposes. However, the terms of fair use is defined differently by different jurisdictions.
2) Which leads us to the fact that copyright is defined on a country by country basis. This means that there is no universal definition. There are some treaties that attempt to harmonize things, but they are not universal and they don't completely solve all differences. Furthermore, in practice some countries are known/believed to blatantly disregard copyright. Whatever, the exact law, it is fairly easy to obtain copies of copyrighted works in China and India, for example. This makes it hard to protect works in these markets.
3) Works need to be translated into various languages. The translated work can have a unique copyright from the original work. I'm not up on this, but I imagine it could lead to more confusion as to whether a work is a translated copy of an original work in another language, or whether it is a new work that happens to have a similar plot. However, even if it is admitted to be a translated work, it has its own copyright that is separate from that of the original work. For example, many editions of the Bible are in the public domain, but if you were to publish your own edition that was translated/changed from an existing edition then your new edition would have its own copyright.
4) Many of the problems with global copyright are actually related to business arrangements that are influenced by all of the above, but are separate from those factors. When it comes to selling a book in a specific country (Russia, Australia, Germany, ...) a company that is successful in the United States often does not have the reach to succeed in another country. The issues include legal (navigating local copyright issues), language/translation, distribution (where are books sold in that country), printing (no reason to ship those dead trees worldwide), and marketing. So the rights to local marketing are licensed to local/regional publishers who are experts in a given market. The issue that arises is one of trans-shipment between regions. A US publisher doesn't want to invest in marketing and then see all of their efforts undercut by a cheaper edition from Australia. Therefore, these license deals are made to be valid only in the region of the deal. This means that a US publisher can only sell in the US and an Australia publisher can only sell in Australia. However, this also hinders global efforts, and it is a reason why internet web sites (who offer products to the world) have geographical restrictions. Their US source is not allowed to sell books to anyone who sells outside of the US, and so on.
The simple answer to the previous dilemma is to license print versions to print publishers and to retain a global ebook license. However, the publishing business is all about high overhead and low fixed costs. Once the publisher spends time finding, editing, marketing, and producing a book they need to spread those costs over as many books sold as possible. With the shift towards ebooks, this means that the publisher needs rights to both print and electronic versions in their territory or they can't make money. As a result, the geographic restrictions on print books have also encompassed electronic books. This is why you will see an online bookstore only letting buyers from a specific region buy a specific edition of a book.
MLH