"ripping" is the act of extracting the audio data from the CD to a computer.
If on a HDD it by definition cannof be "CDA" format, but is similar...
It's usually refered to as WAV or PCM format.
If the music is already on your HDD you don't need to "rip" that's already done, what you need to do is create compressed files.
That can be done with many more software packages than I'd personally care to name.
My personal preference is to use a program called "Switch Sound"
and though it's commercial software ($29) there is a downloadable trial version that works with full features for ~10 days then defaults to a "limited" free edition after that time.
I like free... and basically don't miss the things it won't do.
Creating mp3 files is only part of the battle, you'll also be well served by creating/editing the id3tags.
For that I personally use a progam called "TagScanner" (free downloadable) which works better than ANYTHING I've ever seen.