Licorice can come in a root form or as an extract. The preferred method of taking Licorice is as a tea. A single daily use is the recommend dosage for most people. 1-2 grams of ground root is the amount to use if you are brewing loose tea. About a teaspoon of extract will provide a similar result.
Licorice root does have potential negative side effects so make sure you stick to the recommended dosage and if you notice anything wrong stop use immediately.