Setting Permissions

I've got what is probablly a simple/dumb question. How do I (or is there a way?) to have new files in a directory granted group write privledges as soon as they are created? I'm running Suse 6.4 and Samba on my file server and want to have a certain sub-directory (My MP3 storage) granted group write privledges as the CD-Ripper/MP3-Compressor creates the files. I want to do this so that files can have their ID3 tags updated by a Win98 box that logs in as a different user but a member of the same group. I've tried having CRON run out periodically and update that directories permission settings but I think it would be smoother the other way.