Your instructions for copying the file should work fine, except the flags for mount come before the directory (and -w is default, so you don't need to use it anyway). You can just do this from /home:
cp /mnt/cdrom/rsync-2.6.5.tar.gz .
The dot, by the way, is an abbreviation for whatever your current directory is, so it's copying from /mnt/cdrom to the current directory.
As far as extracting it, zcat is just going to un-gzip it, but it's tarred as well. The right command would be "tar zxvf rsync-2.6.5.tar.gz" (z mean un-gzip, x means extract from a tar archive, v means be verbose and list files as they are extracted, and f means the filename follows next). This should create a directory in the current directory named "rsync-2.6.5" with the extracted contents inside.
Actually, -w means mount read/write, and you can't do that with a CD in the first place.