If you mean update like get the newest version. you need a live internet connection. to check if there is an update available head on up to the apple icon in the top left corner click it and head on over to software update and follow the on screen instructions
You do not have to delete itunes to upgrade. Simply click HELP > CHECK FOR UPDATES
Upgrading iTunes is free.
You do not have to upgrade to Safari 4. It is optional.
Upgrading from iTunes 10 to iTunes 11 will not remove any songs from your library.
It won't harm anything, if you are really worried and don't want to update it, don't update it, or you can just wait till the next upgrade to upgrade the iPhone.
When iTunes is upgraded, it preserves your music library so just run the upgrade process and you'll be fine
Yes.
Click on 'Update' in iTunes!
connect it to iTunes then press upgrade
You don't have to upgrade iTunes, you just can set your ipod touch to a "replacement" even though it's not.
Upgrade to iOS 4 in itunes.
you have to wait for the offer to come up in the store saying that some items may need you to upgrade and then you click it.