iTunes can read wav files. Make sure your external is connected and do the following:
1. Go to iTunes>Preferences>Advanced>General: Change the 'iTunes Music Folder Location' to point to your external's library where your wav files are stored, and make sure both 'Keep iTunes Music Folder Organized' and 'Copy Files to iTunes...............' are both checked. Click OK.
2. Now go to iTunes>Preferences>Advanced>Importing: Set 'Import Using' to WAV, and make sure that 'Automatically retrieve.......', 'Create File Names......', and 'Use Error Correction........' are all checked. Click OK.
3. Go to File>Add To Library...... and point to the parent directory on the external where your files are (the same directory specified above in 1). This will create pointers to all your files in the iTunes xml file (database file). Once complete, all your songs should be in your Library under Music (upper left hand side) but probably with no track info.
That was one way. If you are deciding to re-rip, follow number 1 and 2 above with either WAV or Apple Lossless selected in step 2 ( Apple Lossless is my preference as all track data is stored as part of the file, called metadata), and rip away.
Finally, and this is very important, NEVER start iTunes without your external connected and mounted. If this happens, iTunes will revert to it's default file location (on your local hard drive) and all future rips will be copied here. If this does inadvertently happen, perform number 2 above (and possibly number 3 if iTunes hasn't seen the external in 'a while'), and then go to Advanced>Consolidate Library...... which will copy your local files on to the hard drive.
Hope this helps.
