Use this link for a full tutorial on how to do it and what you will need and where to get them.
http://www.vcdhelp.com/tmpgencsvcd.htm
I've done quite a few svcd's using this method and providing your
original xvid or avi is good quallity your svcd will be as well.
From experience when using TMPGenc to encode to svcd you can get about 34 mins on to a 80min 700mb cd-r so you might have to
use 3 or even four cd's depending on how long the movie is.
If you go for vcd instead of svcd you can get more on to each cd
meaning you will use less but the quallity will be slightly less.