It depends on the format of the mpeg files. If they are already dvd-compliant in resolution, frame rate and type of audio, all you need is an authoring program.
If they don’t fit the fairly stringent specs that are needed, you’ll have to reencode them, then author to dvd-video format.
This page shows dvd video specifications: http://en.wikipedia.org/wiki/Dvd_video
Open your files with Gspot video utility or MediaInfo and see if they match. Both Gspot and MediaInfo are free to download and use. If you are in the US, you’ll need NTSC standards listed in that page at Wikipedia. Most of the rest of the world uses PAL standards.
A simple dvd authoring program is something like DVDStyler, or DVDAuthorGUI.
Use one of these if the files are already compliant.
To reencode and get the end result you want, look at FAVC or DVDFlick. To do the actual burning to the disk, use ImgBurn (Flick and FAVC can use it automatically).
All of these programs are free to download and use. All are easily found via Google.
Use good media like Verbatim 16x, and burn at 8x or 12x speed.