You don't note what Mac, operating system, or version of iTunes you are using. That can be helpful info.
To do a permanent renumbering you will have to edit the id3 tags. If you create a playlist you can order the songs as you wish and they will appear in that same order on the iPod. That way your id3 tags will be as they were for any future need.
If you don't know how to create a playlist then go to the Help Menu in iTunes. It is a great resource and time saver.
From the iTunes Help Menu:
Organizing your music using playlists
You can create lists of songs, called "playlists." You might want to create playlists to suit specific moods, to organize songs with a certain theme, or to group the songs you want to burn on a CD.
You can also include audiobooks, videos, podcasts, Internet radio stations, PDFs, and other items in playlists.
To create a playlist:
1. Choose File > New Playlist (or click the Add button in the bottom-left corner of the window).
2. Type a name for the playlist in the Source list.
3. Click Library, then drag a song (or other item) to the playlist in the Source list. To select multiple songs, hold the Command key or Shift key and click.
Any radio stations in your playlist will tune in only if you're connected to the Internet when you play your playlist.
To remove an item from the playlist, select it and press the Delete key (this does not remove the song from your library or hard disk).
To quickly create a playlist containing selected songs, select the songs and then choose File > New Playlist From Selection. For more tips on creating playlists, click "Tell me more."
To add a song or other item to a playlist, you can also Control-click or right-click the song, choose "Add to Playlist," and select a playlist.
You can also create a Smart Playlist that automatically adds songs to itself based on rules you choose. And you can create folders in the Source list and drag playlists and Smart Playlists into the folders to better organize them. For more information, click "Tell me more."
If you automatically sync your iPod with iTunes, any On-The-Go playlists you've created on your iPod appear in iTunes as "On-the-Go-1," "On-the-Go-2," and so on. If you rename these playlists in iTunes, the next time you sync your iPod the On-The-Go playlists on your iPod are also renamed. For more information, see the documentation that came with your iPod (or in iTunes, choose Help > iPod Help).
MJ
