1. Are you booting level 3 (to command line) or using xdm, kdm, gdm or any other gui login? If so, edit /etc/inittab to use that by booting the install CD or other live CD, then mount the partition that contains /etc, then edit and save.
2. If you didn't set a password during install, just press enter, then set it.
You could boot a live or the install CD, mount your partitions and read /var/log/messages (or whatever the logger you picked writes for hints.