need to download Itunes for Mac OS X Version 10.5.8
Apple web site for Itunes only downloads the latest unable to find Itunes version for this operating system
MacBook, Mac OS X (10.5.8)
Welcome to Apple Support Communities
The most recent iTunes version for Mac OS X Leopard is 10.6.3. If you are using an older version, open > Software Update, and install it from there, or download it from the Apple site > http://support.apple.com/kb/DL1575
If you want to use a newer version, upgrade to Snow Leopard > http://store.apple.com/us/product/MC573/mac-os-x-106-snow-leopard