I have vfapi v1.05 installed on my PC at work and on my PC at home. At work, when I click on Add file, I am allowed to enter file types of d2v, avs from AviSynth or DGIndex, along with DVD2AVI file types and TmpGenc project file types.

At home I am running DGIndex to create a d2v, but I can only enter TMPGenc file types - tpr.

I installed vfapi by running the bat file it came with. Do I need to do something else to get it to allow me to enter d2v files?

Why would you want to use VFAPI? Sounds like you have AVISynth installed, just use DGDecode together with it to frameserve the d2v.

I'm trying to follow this guy's procedure:
http://www.bobsomers.com/articles/dvdmoviefiles4.php

My goal is to convert a PAL DVD to NTSC. I used DVD Decrypt to extract the VOBs, now I'm converting the VOBs to AVIs to use as input to some or all of rebootjim's techniques described in http://forums.afterdawn.com/thread_view.cfm/188000

My PAL DVD has six films on it - I would like to convert two PAL films per new NTSC 4Gb. DVD. That's my ultimate goal.

I haven't found a good procedure that describes how to go all the way from PAL DVD to NTSC DVD - it seems like I need to start with AVIs, so I'm trying to go from PAL DVD -> AVI right now.

You need an AVI? You have the VFAPI AVI. Why not use that? Or better yet an AVISynth script.

VFAPI hasn't been recommended for XviD encoding for quite some time now. Reason being that it forces a RGB24 colourspace conversion. For the same reason VirtualDub filters aren't recommended. Converting to RGB results in lower quality and longer encoding times, therefore it should be avoided when possible. XviD and DVD are both YV12.

Although if you are using TMPGEnc to encode then you are going to need to convert to RGB24 some time. The DGPulldown method would be the easiest. I would just encode directly to m2v though.

I'm sorry I guess this is over my head! What should I do with the ripped VOBs? Are you saying that I should follow rebootjim's suggestion:

Demux the video in ReJig (this will join the .vob's into one m2v video, and one AC3 audio.
Open the m2v in DGPulldown (it's on the Doom9.org site, free).
Use it to convert the video to NTSC.
Load the converted video, and the original AC3 audio into DVDLab.

Or else - how to I encode to m2v directly which you said is better?

How would you recommend that I convert from PAL to NTSC in simple terms? I am new to this, but want to learn the best way even if it is complicated or takes time.

With DGPulldown you still need to resize from PAL res to NTSC res.
I don't convert personally. If something is PAL, I leave it PAL, if it is NTSC, it stays NTSC.

Is your source Progressive or interlaced. For a Progressive source you would normally slow down to 23.976fps, then re-encode the audio, changing its length to match.