Publishing tutorials that customers can follow after the sign up is complete adds more value to any web hosting company. I know that hosts try to expain things in the e-mail they send to new customers but users always need help when they set up their hosting account and features such POP3 mail, FTP and etc. Those are even the easiest service application to work with.
It is different when someone works with MySQL databases, Perl, PHP, Python and etc. People that have knowledge over database management and scripting ususally need to know only the database settings as well as versions of scripting lanugages supported by the hosting provider.
But when a someone sells a hosting service they better to provide information for those who are new in website stuff. You can see how Powweb, one of the popular web hosts, explains the features they support on this page http://www.powweb.com/PowWeb/Products/AutoInstalls. They allow their customers to become familiar with different applications and to choose those that best suit their needs.
It is also a good idea hosts to explain their customers how to work with simple HTML. Check Echoecho’s web site (http://www.echoecho.com/html.htm). The HTML for newbiews is explained very well there.