To start, select File -> New Project. Give the project a name and press "Create project". Just select "OK" in the following dialog box.
Next press "Choose DVD image directory" and select the directory containing AUDIO_TS and VIDEO_TS. You can select "Encode DVD on the fly".
Advance to the "RIP Title" tab and press "Read DVD table of contents". The titles that you are after are the ones with lots of frames. Select them (making multiple selections by holding down the Ctrl key).
Now go to the "Clip & Zoom" tab and press "Grab frame" followed by "Apply preset values".
Go to the "Transcode" tab. Select a DVD title. Press "Transcode".
When it's done, check the finished product. If it looks okay, then select the next title and press "Transcode" again.