>> Am I correct in assuming that putting it on iTunes and then copying to flash drive still wouldn't make them MP3 files?
I would say so. Depends on what you've done with them in iTunes. iTunes supports various formats. You may have put them into AAC format which is what iTunes usually supports.
There are options in iTunes to make files into MP3s but get yourself a proper ripper/converter rather than letting iTunes do it.
If you've got wav files then they can easily be converted into MP3 files.
I suggest you look at the free version of Media Monkey
http://www.mediamonkey.com/ That will convert your music CDs to MP3 files; fill in the tags and do the renaming of the files for you.
Play with that first and see what you can do.