Well its been a few years since I had redhat on my personal machine but for configuring sound you used to have to run a program from the command line called "sndconfig".
Direct 3D or DX is not well supported under Linux. Transgaming has their own implementation that runs along with "wine". If you are looking to get into 3D programming under Linux then look at OpenGL.
If you just want 3D support then Install the drivers fro your card and run native Linux OpenGL games or Windows game via the implementaion of the Win32 API via wine.
Hope this makes sense :/