There are a few methods described on this page for how to copy your iTunes content between computers : http://support.apple.com/kb/HT4527
For syncing your devices to that new computer, these two articles might be of use
syncing with a new computer : https://discussions.apple.com/docs/DOC-3141
recovering content from a device : https://discussions.apple.com/docs/DOC-3991
If the photos are those that you've synced to the device from your computer then you will need to copy the directory that they are in on your computer. If they are photos that you've copied from your device to your computer theg you can also either copy their directory, or (if they are still on it) re-copy them from the device onto the new computer (photos to computer).