When it opens, it should detect that you have a DVD in the drive. If not, then it will ask you for a folder to point to.
Once you have selected the DVD/Folder, you can select which title/chapters to rip. It should automatically pick the longest title, which is usually the movie.
Select a destination directory and file, and click Start. It should give a little status bar at the bottom.
I use it on Mac, so I'm not sure if the Windows version is different.