first of all: relax. Somebody will post. I guess you want to connect your mixer to your PC with RCA cables? If you want to DJ fully digital, you gonna need some more equipment. You need a soundcard, two more audio sources (CD players of vinyl) and some timecode. If you want to beatmatch using your mouse, alright fine, but that is not the real deal of course :p
Check www.djtutor.com, or search for turtorials about DJ software on Youtube.