Newbie install question re: Mouse

[Bob Mills]

I installed Debian Linux 3.0 on a i386 PC using the downloaded CD images.  I had an old serial mouse attached to the PC.  When asked by the installation what port the mouse was on, I wasn’t sure, but answered TTY0, believing that was the serial port.  I also apparently told the installation to install KDE.  When I rebooted, a graphical interface appeared where I entered the user name and password.  I found the mouse didn’t work.  When I hit Enter I was taken to the KDE desktop.  I was unable to navigate without the mouse.  I couldn’t find keystrokes that would allow me to exit KDE, and I manually powered off the PC.  Thinking that Linux might not be able to read my mouse on a serial port I installed a PS2 mouse, but with the same result.   How can I get either the serial mouse or PS2 mouse configured?   2.   How can I get into a command line interface from the graphical login window without the mouse?   Bob Mills