Chocolate should never be melted directly over heat. Instead melt it in a double boiler or keep it in a heat proof/container over a saucepan of water. Check it while melting, let chocolate melt & stir in last with a wooden spoon, so that no lumps are formed. Don't allow any water to come into contact with the chocolate and don't cover it once it is melted, or else the water drops may fall and ruin the chocolate. To melt chocolate in a microwave, break the chocolate into small pieces. First microwave for 30 seconds. Stir and again keep for another 30 seconds. Check again if it requires further melting.
Chocolate are of different varieties :
Dark Chocolate : Can withstand slightly higher temperature compared to the others. Has a high cocoa content.
Milk Chocolate : Contains Milk and has a creamier taste. Care must be taken while melting it.
White Chocolate : Contains lower cocoa butter flavour and cocoa solids.
Cocoa Powder : is unsweetened and bitter and gives a strong good chocolate taste. It has no butter content in it.
To make various design chocolates, after melting the chocolate you may put it in moulds (special ones available for chocolate). Then refrigerate it till set. Then pat it out. Cover and decorate with wrapping paper.
Conversion for Cocoa Powder to Chocolate
1/4 th Cup Cocoa powder + 1 1/3 tbsps shortening or oil (or 2 2/3 tbsps water) = 1 1/3 oz baking chocolate.
This is because baking chocolate has fats while cocoa powder doesn't, so you have to add to it.