Transfer your iTunes library from your old computer to your new computer following the instructions included with this link.
Any photos on your iOS devices transferred from your old computer need to be transferred to your new computer as well.
Assuming all iTunes content on your iPad and iPhone is in your iTunes library on your old computer as it should be - music, movies, tv shows, audio and print books, tones, and 3rd party apps, transferring your iTunes library from your old computer to your new computer per the instructions included with the link provided will change nothing on each device in regards to the iTunes content. It will be like you haven't changed computers.
Any photos transferred from your old computer to each device will need to be transferred from your old computer to the new computer and be re-optimized and re-transferred from your new computer via the iTunes sync process, but the photos will not be lost.
The settings on each device will not be touched. If the backup for each device is stored locally on your computer, the backup for each device will be created automatically the first time you sync each device with iTunes on your new computer, or you can manually create a backup for each device on your new computer without having to sync.