OK - lets get this right... AVI's (or whatever) to DVD yeah?
Well theres your CODEC set for you. DVD uses MPEG2 CODEC - which for pal is 720 x 576 at 25fps. Although you may be better off making NTSC DVD's if the source is 30fps. Either way, I'd use a package called SUPER... which is free (personal choice would be to run it through Procoder 3 and Edius to get super clean upscale, then mark up chapters and "Print to DVD" but it's way overkill)
Get Super from: http://www.afterdawn.com/software/video_software/video_encoders/super.cfm
Then you just drop the files in and choose DVD Standard COmplient as your transcode settings and it should automatically make a compatible video object transport stream (VOB file). I'm not sure if it sets up a transport stream folder and associated identifier files (aka. VIDEO_TS folder and the IFO and BUP files to match). So you might need to drop that VOB into some kind of DVD authoring package to burn the final disk.
There is also an "Automode VCD/SVCD/DVD" drop down in super that might make a fully complient DVD disc ready to go. I've never tried it but worth a go!!