Handbrake should be very simple, unless the DVD has some difficult type of copy protection. However you will probably need a special library to rip commercial DVD's. When I installed Handbrake several years ago, the software automatically prompted me to download this, not sure if that is still the case though.
You shouldn't need a high end PC for this, but a slow one will obviously take longer. I have only used the Mac version, but on my 2011 MacBook Air with a 1.7ghz Core i5 CPU (not terribly fast by today's standards) it used to take perhaps an hour to rip a movie.
The other issue is, how do you want to access the ripped movie on the iPad? The easiest way would be adding it to iTunes on your PC, then syncing with your iPad. If you don't want to go that route, there are some video player apps that should be able to do it.
I find that a high quality handbrake rip of a standard definition movie on DVD is usually somewhere between 1 to 2 gigabytes. So available storage on the iPad may be an issue if you want to use very many movies.