Thanks tt2. Also, I backed the phone up to the new installation on the new PC. Basically I want to move everything on the phone to the new installation. Will transferring the library move everything (Ringtones, apps, etc.)? I'm afraid to sync the device to an empty iTunes as I think it'll wipe the phone clean. Is that correct?
Please read both links fully. If you have your old computer and transfer the library properly from it into your new computer then you will be able to sync as if nothing had changed. If you no longer have the old computer or a backup of its library then the other link should give you a method for extracting all the data on the device into a new library, such that when you restore and rebuild the device from that library no data is lost.
And yes, syncing a device to an empty library will remove all non-iTunes purchased content from it and may involve the loss of other data.