How to Backup and Transfer iTunes Library

Most of us have large iTunes libraries. Between songs, TV shows, applications and movies to your library can theoretically take up several gigabytes of space.

iTunes Backup:
Your iTunes desktop application has a built in feature that allows you to copy your CD / DVD library.
To find the backup utility in the menu, select "File> Library> Back Up to Disc". Of course, if the library is quite large, which may require multiple CD or DVD on white, a little time and, of course, on a CD / DVD. This method creates a backup of your entire library (except sound audio books) or incremental backups.

External or secondary hard drive:
If you have a large capacity internal or external hard drive, you can simply copy the Library folder directly. Select the "Advanced" tab and select the "Keep iTunes Media folder organized" and "Copy to iTunes Media folder when adding to library" option. Then choose "File> Organize Library" menu. Select "Consolidate files." You can now close iTunes and navigate to the iTunes library folder. You can find your iTunes folder in its default location (/ Users / username / Music on Mac OSX, \ Documents and Settings \ username \ My Documents \ My music \ Windows XP or \ Users \ username \ My music \ windows Vista or 7) unless you specified a custom location.
Copy the entire folder on the external USB hard drive or a secondary internal drive. Once done, you have done successfully in your iTunes library.

If your intention is rather to transfer your library to another computer, simply connect your external hard drive that contains your iTunes library and copy it to the new computer in the default location (/ Users / username / Music on Mac OSX , \ Documents and Settings \ username \ My Documents \ My music \ Windows XP or \ Users \ username \ My music \ on Windows Vista or 7) or a prime location, if desired. After this is complete, launch iTunes while holding down the Option key (Mac) or Shift (Windows) and select "Choose Library ..." in the dialog box. Select the iTunes folder you just moved.

Here are two recommendations:
Sharepod (free):

Sharepod is a free application that allows you to quickly and easily manage files on your Apple device (iPod, iTouch, iPhone) or save.

CopyTrans 4 ($ 19.99):

CopyTrans is a very good application. Compatible with all devices and iTunes 10, which allows you to backup or transfer all files.