You cannot normally have an indefinite article before these words: advice, information, news, furniture, luggage, money. You need to have a piece/bit of advice, etc, an item of furniture.
If you have an indefinite article before these nouns, you normally mean a type/variety/brand/serving of: rice, sugar, butter, water; music, art, happiness, electricity, love.
gas, power and currency are frequently used countably.
- For Teachers