How can i connect my mixing desk to my computer? HELP?

Can you tell me how?

There are two ways to do this.

one – connect the red/white RCA tape outputs of the mixer to the line input of your computer (blue connector) using a standard 3.5mm to RCA cable:

http://imgs.inkfrog.com/pix/extraps/35rca.jpg

A better way is to use a simple USB interface – this will give you much better sound:

http://www.zzounds.com/item–NUMSTEREOIO