Wood67
Welcome to the forum ksned.  This is a common question (in fact there's a similar thread going on right now), and you will receive a lot of suggestions.
 
The best place to start is with your budget, and the connection you plan to use (USB, Firewire etc).  At around the USD100 level you will find external USB soundcards from folk such as Focusrite that will probably more do than do what you need, as well as including a couple of line ins should you wish to attach a mic or guitar input.  As you move up the budget you will find the RME Babyface (that's where I am now) that have better A/D converters, SPDIF and lower latency, and an increasing number of inputs/outputs.
 
I don't know exactly what your requirements are, but I would *suggest* an external USB soundcard, with 2 mic/line ins, a pair of balanced outputs and a headphone output.  Something like the Focusrite Scarlet 2i4 maybe?  That would certainly be a world of improvement over the stock audio card in the pc.
 
<EDIT> for poor grammar, spelling and other stuff that makes Strummy mad!