Sorry, I should specify which of your questions I'm answering.
groff is used to compile/format man pages stored in groff/nroff form, converting them so that they can be displayed or printed. When you look at a man page for the first time (e.g. man fsck) groff compiles the man page into a printable version, and stores the compiled version in one of the /var/man/cat directories (e.g. /var/man/cat8). If you didn't install groff, then you can't view man pages.
The HOWTOs are stored in /usr/doc/Linux-HOWTOs/ and /usr/doc/Linux-mini-HOWTOs/ . These are plain-text files, so you can edit them or use the less (or more) command.
Just press the enter key to accept the default of /bin/sh when adding a user.
To give yourself permissions to mount the cdrom, edit the /etc/fstab file and add the "user" option. Here's the entry out of my /etc/fstab file for the cdrom:
Code:
/dev/cdrom /mnt/cdrom iso9660 user,noauto,owner,ro 0 0
Finally, to answer your original question about the log saying the disk is read-only, are you talking about the line that says something like: "VFS: Mounted root (reiserfs filesystem) readonly"? Look in /etc/lilo.conf and you'll see a line that says "read-only". Lilo initially mounts the disk read-only so that the boot process can check the filesystem (fsck). Later in the boot process the disk is remounted with read-write access. You can see where it remounts the disk in /etc/rc.d/rc.S. The /etc/rc.d/rc.S file is defined as the system initialization script in /etc/inittab, which controls init (the "mother of all processes"). init is the very first process started when your Linux system boots. That's why it always has a process ID of 1. Do "ps -A | grep init" to see that. In summary:
1. Lilo mounts your disk read-only
2. init is the first process launched
3. inittab tells init that the initialization script is /etc/rc.d/rc.S
4. /etc/rc.d/rc.S does a fsck if the disk is mounted read-only (which it is), then remounts the disk read-write.
Hope that answers your questions!