There's many programs to rip, such as iTunes, Media Monkey, EAC, Musicmatch. They are all free.
Now if you need to burn back to CD and do not want to lose audio quality, then you need to also make a lossless rip of the audiobook (either in WAV or FLAC format). Otherwise, you can still burn a CD with the MP3 files, it will just be in downgraded quality, as compared to the original file.
I use EAC for all my music and audiobooks. I also make separate MP3 (for playing) and FLAC (for archiving) files. But EAC might be overkill for what you want.