how do i convert my microsoft zune library to itunes?

It might have helped if you mentioned what format the music is currently in.

If they in MP3 format, then no conversion is required, since iTunes (and iPods) can play MP3s.

What you may need to do is turn on the top bar menu in your iTunes. For some strange reason, although you have a MacPro, you've put your question in the iTunes for Windows forum, and in Windows, the shortcut to turn this feature on is CTRL+B. So if CMD+B doesn't show the menu bar, click on that tiny icon in the top left corner of the iTunes window and select Show Menu Bar.

From that menu bar, select File/Add Folder to Library and navigate to the folder (or folders) with your music.

iTunes can also play other formats, as can the iPods. Whether you find them suitable or not, I don't know.

I'm unfamiliar with a Zune, but if it's like other MP3 players I've had, they do have a file manager so you should be able to plug the player in and use finder to navigate to those folders and drag the music off.

Once you get those files onto your mac's drive, use the instrutions above to import that music into iTunes.

If the mac wont' see the player then you may need to use a PC to drag those files off the player and onto something to get them into your mac.

You might also look to see if hte zune has a desktop interface that works on a mac. I have a creative zen and another type of media player and they have file managers on them, so computers just see the devices as an external hard drive, which is what enables you to click and drag the files.