Hey everyone.  This is my first post to this forum.  Please forgive my ludditious tendencies.  I'm analogue at heart.
After 10 years of vinyl djing, I am ready to embark into the digital realm wiith my mp3's, but have no idea how.  
I use a 867 Mhz PowerBook G4, OS 10.4  246 MB RAM (hopefully soon to upgrade)
I have just tried Native Instrument's Traktor software, and I am impressed.  I managed to get a basic understanding of how it works, with the exception of the cue function.  
I seem to gather that I need an external soundcard or something of the sort.  What I need to do (right now) is to cue one channel in headphones, while the program is going to an amp (or mixer).  What is the best way to accomplish this.  I normally feed my computer to my mixer through a simple 1/8" (mini headphone) jack to RCA cable.  
I am really in the dark, and what I would really like is a description of your setup(s).  Any software recommendations are also appreciated.  
Thanks in advance, 
J.Knecht