There are so many articles in the Internet (type
Mac OS X virtual machine to Google or your favorite search site to get thousands of them) about running OS X on PC in VirtualBox, that writing another one is just a pure stupidity. Instead, this article includes only a quick check-list to extract essential information from these articles and leave all unnecessary garbage blah-blah behind.
This post is a short version of this article. Refer to it for all details, explanations, solutions for a possible problems and things like that. This guide assume, that you’re installing OS X inside a virtual machine only for one purpose — sending your iOS apps to iTunes through ApplicationLoader program. For this reason, certain parts of original guide are skipped. If you intend to use OS X for other purposes, you may need to enhance your knowledge, by reading missing parts from other sources.