Hmmm, you need to read up on intellectual property.
First, you do not need to be a business to have a copyright. Technically speaking, this message I am typing has an implicit copyright. By default, implicit copyrights are the most restrictive type (the author reserves all rights). I really do not remember if I agreed to give up that copyright to my posts when I signed up on this account, but technically speaking that would be the only way I could not have an all rights reserved copyright on this message by default. As long as you create something that is not trivial, it is copyrighted. Although all intellectual property laws exist to give the original author a temporary monopoly over their creation, you do not need to have a business intention in order to be protected.
Having said that, you need to do things to protect your copyright fully. If you want to collect damages in case someone violates your copyright, you need to register your original work with the USPTO (Assuming you want your copyright registered in the USA). Read this for some key basic information: http://www.uspto.gov/smallbusiness/copyrights/faq.html But I think you need to take a step back and survey the intellectual property landscape: Maybe what you really want to do is to protect your idea in the way that patents protect ideas. You need to understand the difference between a copyright and a patent. After you do that then understand the differences between copyrights/patents and trade secrets.
After you understand the basic differences (and how those apply to your situation) you need to get caught up on current events such as pending litigation that might invalidate business method patents, which is the type of patent that has protected programming-based inventions.
Also (as if all this was not enough already), you need to understand that intellectual property laws and protections do not get you customers or make you profitable. Being quick to market and satisfying a real need is what makes a business. Between being first to market and having a fully-protected idea, you should always choose to be first to market, for example.
I understand your desire to protect your idea, but intellectual property protection is a field that requires some study, so you need to do some homework. Ask here if you have any questions.
Really two different questions:
Q1: What is required for a website to be elible for copyright? Here is a good article that discusses the legal issues involved with the creation of a website.
Q2: what is required for an idea to be eligible for copyright? You don't copyright an idea - you patent it.
If you truly believe that your idea is patentable and are concerned about protecting your idea, you need to document when you first thought of the idea, provide proof (napkin sketches with dates are even acceptable), and write up a provisional patent application. At least, that will define the timeline when you first thought of the idea. You then have 1 year to make good on the idea and draft up a real patent.
Also to consider - a lawyer mentioned to me "a patent is only a hunting license - you still have to have guns and know the terrain."
Sure, you may have a patent, but you need to develop the idea, deliver it, and protect it against others who would infringe on its various claims. That requires a lawyer - and the money that goes with litigation.