Copy the full DVD onto your hard drive. This is what "ripping" a DVD actually refers to (not converting it into another format). The video on DVDs is in a special format called mpeg2, sort of similar to mp3 for audio files. Mpeg2 makes video files small enough to fit on DVDs (they are actually even bigger than these very large DVD files. Before we can deal directly with the video information, DVD's have a number of copy prevention mechanisms. When you rip the DVD you strip off those mechanisms, but copy the rest of the video unadulterated. This means that the ripped DVD will take up as much space as the files on the DVD itself. In order to successfully complete this process, you need to have a minimum of 5 gigs free after you copy the DVD(s) to your hard drive. Unless you run out of free hard drive space, you can keep ripping DVDs to hard drive before progressing to the next step of this process.
Find out whether you have enough hard drive space:
Select the DVD in the finder and then press: command (apple key) - i to get info about the disc. Check out the used space to see how large the disc is.
Click on the hard drive you are saving the files to and use the same technique to see how much space is available.
If you have 5 gigs more available space on your hard drive than used space on the DVD, you can rip another DVD before progressing to the next step. Otherwise, skip to step 2.
Now that you have a ripped DVD file, you need to make it fit on a single-layered DVD. Normal commercial DVD discs have two different laser-readable layers, which means they can hold nearly twice as much video information. Burnable DVDs and most burners cannot support this new (and significantly more expensive) technology and can only burn the half-size 1 layer burnable discs. We achieve the size reduction by means of "transcoding" each frame of the video. This means we break up the video by frames and reduce the complexity of the video information by a certain factor in every frame, thus making the video files smaller by the factor. This process is faster than converting the entire movie again. It does mean, however, that discs made by this process will sometimes look noticeably worse than the discs that they are copies of. This cannot be avoided (and this method is also the best looking one (better than re-converting the entire movie to DVD format).
BURN THE DVD:
Open Disk Utility (in your Applications folder (apple-shift-u)).
Locate the Image that you made in the DVD2OneX step in the Finder.
Drag the DVD image to the sidebar of disc utility.
It should appear under a divider. Select it.
Select Images > Burn...
Insert a burnable disc.
Select Burn.
Burn at speed Max.