the next step from extracting a WAV from CDA is compressing it and ecoding it into an mp3...it's important to get a good encoder, otherwise sound quality will suffer....LAME and Fraunhofer seem to be the best....I hear that Xing [Audiocatalyst] has got a serious problem with high frequencies, turning them into garbage...so make sure you get a good decoder, and give your system enough resources to encode mp3's without any problems..
next, is your mp3 player......winamp and foobar2000 have pretty good mp3 decoders......however, just because you have a good mp3 software player doesn't mean that there will be no clipping.....your system needs enough resources to play mp3's without clipping...you might notice that whenever you surf the net or do some other operations that require a lot of memory and CPU time, sound quality will suffer and you'll hear a lot of clipping.....increasing the buffer size for the mp3 decoder can help solve this problem, but may make things slower on your computer.....
anyway...that's all the help I can give...if that's any...hope that works!