If everything went as planned, you should now be able to boot Linux from the hard drive using LILO. Alternatively, you should be able to boot your Linux boot floppy (not the original bootdisk floppy, but the floppy created after installing the software). After booting, login as root. Congratulations! You have your very own Linux system.
If you are booting using LILO, try holding down shift or control during boot. This will present you with a boot prompt; press tab to see a list of options. In this way you can boot Linux, MS-DOS, or whatever directly from LILO.