iOS 7 isn't available on 4th gen iPod Touch
no but you can get it on a iPod 5
No, you can use iMessage on a 3rd and 4th gen iPod Touch running iOS 5.
No, the update is only for iPhone 4, iPod touch 4, iPad 1, iPad 2. The highest version iOS Firmware for the iPod Touch 2G is 4.2.1.
Sadly, no. The latest version of iOS for the 4th Generation iPod Touch is iOS 6.1.5.
You cannot. The iOS 5 update is only for Iphone 4, iPod touch 4, iPad 1, iPad 2
Upgrade to iOS 4 in itunes.
You have to upgrade to iOS 4 Firmware for free
This only works on iPod touch third generation, iPad,or iPhone and you have to have iOS 4. If you are using the second generation, you will have to jailbreak you iPod touch.
iBooks if available on 2nd, 3rd and 4th generation iPod touch with the iOS 4.0 update or higher. Since 1st generation does not support iOS 4, iBooks is not supported for 1st generation iPod touch.
mmm the ipod touch 4g already come with iOS 4
You can update it to iOS 5 the same way you update it to any other iOS version. The 4th generation (and indeed the 3rd generation) iPod Touch can be updated to iOS 5.