To save photos and other files (not apps) on the SD card you need to go into whatever app you are using to create the photos and change the settings within that app. That is the only way to get them to change where they are saved.
If you want to just move files (photos, videos, music, etc.), not apps, to the SD card you can use the file manager app that is on the device, or if there isn't one you can download and install one to access and move the files. Sadly, they usually only let you move one or two at a time.
To move them all at once, or in large amounts, you can connect the phone to a computer via USB cord, then move the files over to an empty folder on the computer. Once there, and still connected via USB, you can then move or copy the files over to the SD card. Personally I would suggest leaving a copy on the computer as a back up.
Once that is done you should then go into the apps that you access the files through (like gallery, etc.) and change the apps individual settings to look for the files on the SD card.