Converting MP3s or any other lossy compression audio file to a lossless format does nothing. Once the codec removes parts of the sound it thinks you wouldn't hear it is gone forever. When you convert it to a lossless format, it is still the same audio just in a different form and nothing that was removed from the original can be put back.
There are many programs available for playing music in various formats: Windows Media Player, WinAmp, iTunes, etc. Many of them can also rip CDs. If your computer is connected to a receiver you can play any files on the computer and have the audio sent to the receiver.
If you want lossless audio, when you rip the CD either save the file in WAV or AIFF (if on a Mac) or use a lossless compression codec like FLAC, WMA lossless, Apple Lossless, etc. The lossless compression algorithms will cut the file size in half but of course you need a music player that recognizes the format so it can decode it to PCM.