First you need an understanding of what VFR is, start by reading these:
http://forums.animesuki.com/showpost...87&postcount=1 (or rather read the complete thread, on page 19 Mentar explains a bit about YATTA)
http://avisynth.org/mediawiki/VFR
After that, I can't really help you. If you have specific questions someone will probably answer, if you ask here, but I don't think there's any "VFR for dummies" out there.
Also read up on the difference between mere interlacing and telecining. Without understand these two, you will never be able to do anything properly.