So ‘ight, time’ta back up files to prepare for a Redsn0w jailbreak. In case iTunes doesn’t backup some of the files it’s meant to, use iBrickr to backup these files…

/var/mobile/Library/AddressBook – Contacts
/var/mobile/Library/Calendar – Your calendar
/var/mobile/Library/Notes – your notes database
/var/mobile/Library/Safari – your bookmarks and cookies
/var/mobile/Library/SMS – your text messages.

Note that iTunes will not backup your notes for a fact (until OS 3.0), so you might as well back all the rest of these things yoursel.

Peace, J