The classical technique to melt chocolate is to use a double broiler (also called bain Marie). However, I am deeply convinced that using a microwave is significantly easier and faster.

• chocolate to melt
• a tablespoon of water (you need some water to prevent dry burning but too much will deteriorate the result)
• if the recipe calls for melted butter, adding cream or milk, you can replace the water with one of those in the quantities required by the recipe

• put the chocolate in a small bowl
• add the liquid or milk produce
• microwave until the chocolate is softened (around one minute depending on the strength of your microwave)
• mix the result to finish melting the chocolate

I am not aware of any particular credit for this technique, I saw it used by a variety of sources.