Can Yellow Dog Linux co-exist with the Mac OS on my drive?
Yes, you may have Mac OS and YDL on the same drive or have Mac OS on one drive and YDL on another. It is entirely up to you. You can setup a single drive with YDL, Mac OS 9, and Mac OS X as described in the Guide to Installation. When in Linux, you may mount (access) the Macintosh HFS partition (or drive) from a command line or run netatalk, an AppleShare server.