Use a program like 'DVD Flick'. Load the source file. Set options like whether you wish to burn the disk after conversion or add subtitles. The program has a concise guide that lists the steps required. A very important step is in the 'Project Settings' => 'Video Format' => choose either NTSC (North America) or PAL (EU and Australasia) - generally speaking, a PAL DVD will not play on a North American standalone player. http://www.afterdawn.com/software/video_software/dvd_tools/dvd_flick.cfm
If you want to convert the divx so that it fills the entire screen and not have those black bars on top and bottom, the only program I found that can do that is convertxtodvd 3.0. Dvdflick is good and it's free, but it couldn't get my divx to fill the entire screen when converted.
I'm a newbie, myself, so take it for what it's worth, but I'm confused by the answers you got to your question. When I want to make a playable DVD from a Divx file, I simply burn it to a DVD as a data file, exactly the way it is. Most newer DVD players recognize Divx, and just play them. Mine have worked fine. If I'm doing it wrong, I'd like to know that, too.
You aren't making a playable DVD you are simply burning a DATA disc. I would also assume that most do not own Divx players.
I could be wrong, but these days, even the low end dvd players seem to list Divx on the box. They apparently play Divx files, in the same way that they play MP3 files. I have the cheapest DVD player I could find, it's a couple years old, and it plays the Divx video files I burn to DVD, just fine. I don't pretend to understand this stuff at all, I don't know the difference between the different file types, and I don't know what makes a DVD file different, but as long as I can archive a video in a form I can easily watch whenever I want, I'm okay with it. Obviously, videophiles may want to follow another route. I'm just saying that anyone who just wants a decent copy to save, it works.