i've never used Black Cat Oil, but check out luckymojo.com, i know they sell the stuff and they have information on their products.
i don't know what you wish to 'put it on', but you anoint candles, objects, and people with oil to give them extra energy. the oil is infused with the energy from the plants, so a small amount should give a lot of energy as a result. put a few drops on your index finger [of your power hand] and rub in a circular motion the oil over the object, visualizing your intent. if you;re anointing a person, it can differ with each spell, but normally, you put a drop on your wrists, ankle and neck. [some people i know also put it behind the ears] you could also use to to draw symbols or whatever else, but that's the basic anointing i know.