The true genius of DotNetNuke is its modules.  Modules are controls that house the different types functionality of your website.  There are people and businesses that do nothing but develop modules for DotNetNuke.  If you find yourself needing a piece of functionality for your website that the built in DotNetNuke modules can't accomplish, chances are there is a module out there that can.  DotNetNuke modules can be purchased from many sites, but these two are definitely the best.

One of the best aspects of DotNetNuke is that it utilizes skins.  Skins act as the skeleton or layout of your website.  Many people do nothing but develop skins for a living and it truly is an art form.  Skins are relatively simple to develop, but coming up with the graphics for the skin is an expertise that only a handful of people have mastered.  Click here to take a look at some of the skins you could use.