Sounds like your cdrom is getting flaky, it won't read the boot part of the disc.
Since the install did complete, you may be able to rescue what's there. At the boot prompt, highlight the VL menu entry with the up/down keyboard arrows. Press Tab so you get an editable line. Add "2 vga=normal" and press enter to boot. Let us know if that gets you to the command line login.
Nightflier's suggestion seems like the 1st choice of action here. Alternatively, I think you cdrom could be a long term problem. I imagine this is a desktop. Can you get you hands on an alternative (should be able to pick up a used one for $5.00-$10.00 bucks, even less.) cdrom drive and switch it out. Then try your boot disks again? If no problem then I think it's safe to assume the old cdrom is ready for retirement.