Depends on what you consider good quality.
VCD quality MPEG-1 - you can get 60 minutes on a 600MB CD-Rom or more if you use the 74 minute CD-R's
If you go with higher bit rate SVCD or MPEG-2 DVD quality
you get less.
You can find more info here:
http://www.vcdhelp.com/vcd.htm
(Scroll to the bottom for the chart)