There was a fair amount of info in one of the FMWebSchool newsletters.
There are links to 2 movies about it on that page. There were also example files, but I don't know how you'd get them; I don't know if past issues/files of that newsletter are available; perhaps if you write to them.
Thanks for the tip. I have contacted John Marc and his site http://www.databasepros.com/FMPro has a very nice example under Resources Tab in the file GCHART which is very helpfull and is unlocked.
He certainly is a very generate person and has tons of free helpfull stuff about filemaker on his homepage.
Here is another example I like, at Ray Cologon's wonderful site. It is for a fairly simple vertical bar graph. It uses mostly HTML, so some knowledge of that is useful if you want to modify the graph much. I think the HTML could be cleaned up and made more modular. I did a little of that for myself; but I'm no HTML expert, so it was somewhat tedious. What I like about this particular example is that it prints fairly cleanly. Many of the other types of graph methods can produce complex nice looking graphs on the screen, but they print kind of fuzzy.
Kudos to Fenton. Your link, though very old, rendered the information I needed to create a Google Chart using HTML. Thanks.