I don't know what kind of CD/DVD to download ?

[Google-Summer.]

Hello,I'm a Chinese student. I want to use the Debian. But I don't know what 
kind of image to download. My computer is Macbook Pro MD102. Inter Core i7 
3520.     8 GB 1600 MHz DDR3.       Intel HD Graphics 4000 512 MB. I will very 
grateful if you can give me a download link. I hope you can replay soon.