You cannot. Names, titles, and common words/phrases do not qualify for copyright protection. However in some cases the are registered as trademarks.
In this case the phrase "for dummies" is already trademarked (serial #78615850, reg #3167658) by Wiley Publishing of New Jersey.
There is a widely held, but incorrect belief that copyright does not apply when the work has been published on the internet, or that it does not apply if there is no copyright notice on something. There is also a popular myth that you cannot be sued for copyright infringement if you don't make any money on the unauthorized copies you distribute.
If copyright law did not apply to the internet, it would be nearly impossible to monetize anything on it.
Copyright law wouldn't apply to a skin care product, as it is not a creative work.
playwrights
One must apply to the copyright holder for permisson to use their copyrighted item.
The copyright law of the country in which it was created would apply.
No; protection is automatic as soon as a work of sufficient originality is fixed in a tangible medium.
I would suggest Step by Step Windows Editon copyright 2001 Windows for dummies by Andy Rathbone is also good
Most definitely
You probably wouldn't want to copyright a product; you might want to trademark it, or (if it's revolutionary) apply for a patent.
It varies from country to country. In the US, for example, it is US Code Title 17, the Copyright Act.
No, anyone can apply for a copyright, but the vast majority of copyright owners do not bother to "apply" for anything because copyright ownership is free, instantaneous and automatic upon putting your creative work of authorship into any tangible form. That is the law in over 160 countries under the Berne Convention. In most of those countries there is no possible way to "apply" for or register any copyright, but in about 50 countries you may register your copyright, which is not the same as "applying" for it, since you are just putting your existing ownership into the official records. Registration in the USA is only required if you are planning to sue someone in federal court for infringement.