Mike, the answer to the question you asked is that almost any sound card
will work fine with 8.04.  That's why he must ask for your specifics to have
any real hope of providing you with a useful answer.

Further, 8.04 is two releases back so one might ask if you had a reason for
using and old release which might support fewer hardware variations.  Now
you might have a reason such as that 8.04 is a long term support (LTS)
release and you are installing in a business environment.  Regardless,
another thing worth trying is to boot a 9.04 LiveCD and see if your sound
works with it.

So, describe your machine hardware and post the result from what Matt
suggested and perhaps we can give you some help.