The Debian Project has a very large and well-defined support structure that includes a lot of documentation, a Wiki, mailing lists and newsgroups, websites, and forums. live help is available on IRe, and there is a well-developed and effective bug tracking system, usable by anyone. It is also possible to contact Debian developers and package maintainers directly, something not always possible with other distributions. These and other available support resources may be found at http://www.debian.org/support.
The thing to remember is that these are volunteers (some of them are, in fact, paid by companies that officially donate their time to the Debian Project). A major release occurs about every two years and is supported with updates for three years, or about a year after the following major release. The response to bug reports and support requests, in my experience, is quite good, and sometimes faster than paid support. Of course, the quality of advice in places like the forums varies with the experience of the person giving the advice. Nevertheless, this works very well for the majority of users. The fact that Debian releases are extremely stable, to begin with, help.
For those who prefer to pay for support, there are a number of companies and individuals that provide such a service. In fact, the Debian website has a page that lists such consultants all over the world.
In a similar vein, although Debian is freely available by downloading from any of the numerous Debian servers and mirror sites, and burning one's own set of installation CDs, DVDs, or Blue-ray discs from the images so obtained, it is also possible to purchase ready-made installation media from third-party vendors.
