I just ordered a new computer and I wan to transfer all my apps music and videos straight to iTunes or at least to the computer. Keep in mind my iPod is not jailbroken. I know there is a backup iTunes option in iTunes but does that work for everything. What I mean is if I back it up to disc will that work? If there are any other ways please let me know.
An external hard drive would work to transfer the data; just plop the content into the external and from there to the new computer. You could also hook both computers up to your home network and transfer the data between the computers that way. I don't know if backing up to a disc works for everything. It would probably be more worry-free just to use an external hard drive for it, just for the sake of knowing that all the content is there.
For OSX: When I got a new iMac, the "migration assistant" app moved all my itunes content from my old MacBook Pro. The only thing I had to do was login to itunes and register my new computer (you can have up to 5 computers registered).
I remember that if you want to save all your metadata, eg playcount, you need to copy your itunes.xml file over. Search on google for full tutorial?