Nook: How to use any font in ePub reader

The ePub reader application of Nook provide the feature of choosing one of the 3 font families included (i.e.: Amasis, Helvetica Neue, Light Classic).
But there are many reasons why one would have the chance of using other fonts for viewing his own ePub documents:

• the standard fonts are not able to correctly render all the characters used in some languages (for instance, eastern-europe languages based on Cyrillic alphabet);
• you may find more readable, or simply like more, other fonts;
• you just want to have full control on any geek gadget you own.

You can find the complete procedure here.