nikki -
First of all, can you play / view the AVI on your Mac?
The reason I ask is that not all AVIs are 'created equal' (or any movie files, for that matter, but especially AVIs, which are Windows "Audio Video Interleaved" Multimedia Files).
Movies are encoded to play on computers with a piece of software called a 'codec', and there are many different codecs in use, some of which result in computer movie files that will not play on Macs for love or money, because the particular codec has never been made available in a Mac version.
If the AVI does play on your Mac, the process for making a VCD using Toast 5 Titanium is pretty simple:
Open Toast and select the Other icon, then select Video CD from the list. Drag the AVI file into the Toast window. Toast will convert the file into the necessary format. This can take some time if your Mac is not a fast one or the movie is long.
When this conversion is done, click the red Record button.
FYI, according a Toast ReadMe file I found, even though a particular DVD player claims to support the VCD format, it might not play one that's been burned on a CDR, or it might be 'fussy' about the brand of CDR that you use.
hope this helps,
- kbeartx