I got a new cactus- how to care for it?

Question

http://tinypic.com/view.php?pic=2vwusdc&s=4

I bought a cactus today, and I'm not sure how to care for it. The above link is a picture of it. It is about 7 inches tall. How often should I water it, and what sunlight is best, and how much?

Answer 1

http://www.ehow.com/how_2179133_plants-c...

http://www.alexandgregory.com/cactus_exp...

I hope it helps.