I love easy questions like this one...your wish is my command.
When you first open Fab and put a DVD in your drive, after Fab has opened the disc, you'll note that the 'Source' is filled in by the program. (you're looking at the screen as it first appeared when it started.)
Right below the 'Source' line is the 'Target' line...just click on browse, select a folder of your choice on the harddrive of your choice, and click OK.
Make any other adjustments you need (DVD-9 or DVD-5, path player enabled or not, any subpictures desired - or not) and go ahead and rip.
The program will save it to that folder on the harddrive, available whenever you want to view it.
Keep an eye on your HD space, as films are very large (7-8.5 GB) and HD space get eaten up very quickly (especially if you're a movie buff and do alot of films).
If you're doing just the main film, you'll have a couple of more choices to make, but the basic procedure is the same.