For chocolate coatings its 1 tablespoon of grease (shortening, peanut or vegetable oil) to 6 - 8 ounces of solid chocolate and melt them together.
Do not use butter because it contains water.
Double Boiler: Fill a saucepan with water up to the point that the double boiler bowl would rest its bottom in the water when put in place. Bring the water to a full boil and turn off the heat. Place the double boiler bowl filled with chocolate (and grease if you're making chocolate candy coating) on top of the boiled water. Do what you have to do and come back after 25 minutes and carefully stir the chocolate. If it still has a way to go, turn the burner on warm or low to help it along. When the chocolate has melted, carefully remove the bowl of chocolate and wipe off the bottom of it with a dishtowel
Your chocolate mixture shouldn’t boil not even tiny bubbles – instead it should slowly melt together.
Dip or brush on the coating (If you brush it on it will take a few coats

Chill in refrigerator for 4-6 hours (to solidify the chocolate) Or eat immediately (That is the method we prefer around here

).
An alternative to a double boiler (if you don’t have one) would be a large pot with a smaller pot inside – with spoons to hold the bottom of the smaller pot of the bottom of the larger pot – you want to heat the large pot, heating water which in turn heats the smaller pot. Direct heat leads to uneven heating on the bottom of pots – the water distributes the heat evenly in this case the stored heat is being released over a period of time causing a slow melt of the chocolate.
Add NO WATER to chocolate – water, even a single drop can ruin the chocolate - causing it to turn grayish colored, causing it to clump. Shortening is suggested because it doesn’t contain water. Even a hot humid day can present problems.
Microwaves have their place (heating water for tea) however for confections, baked goods, good home cooked meals they are basically useless. In the case of chocolate there isn’t any water in a bar of chocolate to heat up rapidly and evenly enough – so in this case what happened is that you cooked/scorched the chocolate well before it actually “melted”. The nasty flavor was burnt chocolate ;-)