Retail DVDs are harder. There is more data in the VOB files. Wrong extractions make a mess. I don't have time to explain further on what the mess is.
Use freeware
DVD Decrypter, rip as IFO mode.
Follow guide on digitalFAQ.com for this, you need to rip as 1 big VOB file per episode, not the 1GB chunks.
Open cheapware TMPGEnc Plus 2.5, and then demux (NOT SIMPLE MODE) the one audio and one video stream you need. The VOB is full of streams, and those cause messes in re-authoring. I'm not aware of many demuxers that do it at the advanced stream level - most are "simple mode" ones, that only see audio and video -- messy.
Author your DVD as-is. The size of the DVD is whatever it is.
Use freeware DVD Rebuilder, which re-encodes the video down to perfectly fit a SL/4.38GB DVD. It comes with some free encoder that looks almost as good as Procoder. Just use it. Then it'll re-encode down in one step, instead of many steps with another method.
I'm sure other people will suggest quicker methods, but a lot of those are stupid and fail a lot of the time. Much of it depends on the complexity of the source DVD and what streams are in the VOBs. Subtitles, for example, can really screw up things. Or secondary audio like DTS or even a simple secondary audio stream (stereo only, commentary, language, whatever). The method I just gave won't ever fail.
