i've never done a guide to gknot since its so simple i don't think there's even a point, that i recall, that's merely advise on choosing what to avoid doing. Doom9s is a step by step as in a do what they say.
Basic process. Load gknot, on the first tab, click dvddecrypter, extract to a directory on your hdd in IFO mode ~(it tells you how to do that next to the dvddecrypter button), you then load up the DGindex or whatever its called, hit F5 for a preview, when the text appears in the box, you then press escape.
If its NTSC and > FILM 95%, you activate FORCE FILM, it tells you this in the text next to the button. If you don't you will need to IVTC later. If its PAL, do not worry about either. It tells you what to do in the text next to the button.
You open the the file you create with that with open. in the new window, you go to view and make sure its checked that your displaying the resized version
You go to the next tab, you click 1 cd, xvid, 128 vbr for the first audio, you select one audio track, you uncheck the overhead box, you make sure the drop down box says mp3 vbr.
You click the next tab, you select ntsc, 16:9 for anamorphic else 4:3 for letter box. You go to cropping. You hit smart autocrop all and then check smart autocrop all. you then check carefully in your preview window you can't see any black boarders, you can tweak single pixel cropping back on the cropping part of the 3rd tab.
You now look at the resolution, your more than likely going to have to resize down. So drag the slider down to a low 600x??? value.
You now go to the preview window, this is
important. Get to a scene with motion, now advance one frame at a time... if you see any interlacing problems, you will need to apply a deinterlacing filter on the next option. Kernal deinterlace is a popular one. If you have NTSC, and you didn't FORCE FILM, check for this sequence: normal, normal, normal, INTERLACE, INTERLACE. If you get that, then you need to IVTC on the next window, not deinterlace.
If you don't know what interlace means, check the sticky in the higher quality section.
hit save and encode. if you need to deinterlace or IVTC, find the options and enable the one you want
You now look at the bit that says compressability test. You enable it. Then you hit the compressability test button.
You now make a drink and come back.
In the main gui, at the bottom under neath where you cropped and selected a resolution, you'll have a box with some numbers and a percentage in. If its a reasonable number. Drag the slider for choosing the resolution until you get a decent value, about 90% is great.
DO NOT go below 512x resolution though, if its trying to get you to do that don't. Keep it at 512x minimum, and never go above 700~ (where you have a zoom of above 100%).
Once you do that, go to your preview window (if its not there, go to open and open your file again). Hit save and encode. Apply any deinterlacing or IVTC you need. Then hit save and encode again.
You will come up with another window. Here, go to first audio, select your AC3 file that you demuxed right at the begining. Then choose the option that has a re-encode to vbr mp3 kind of feel. I think its the third option down. Go back to the first tab, check the options, then hit the buttton that has a "okay we're about finished" kind of feel to it. It will ask you if you want to encode. and you do, so your done.
Doom9's guide covers all of that, more coherantly and with diagrams. It cant be that hard because i've written this entire post from memory and I don't use gknot that much