There a quite a few tools for that, both free and paid. I use the paid version of dBpoweramp which has great batch conversion, but you could use stuff like Audacity which I think is free. The LAME MP3 encoder is probably what you’ll want to use it with. Make sure you pick 320kbps with full stereo when converting.
Audacity not only converts, but you can edit your wav file before converting it. Which is handy if you have some quiet at the beginning or end of the file or if you want to make a nice fade in fade out.
Pretty much load the wav file into Audacity, edit anything if you want/need to, then export as MP3 with the correct options is how it works, I believe. So nothing too difficult.
Greetinx,
C.
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