It is impossible to protect images.
If you stop people from right-clicking on them, they'll just drag and drop it. If you stop people from being able to drag and drop, they'll just take a screen greb and paste it into Photoshop. Whatever you try to do, there will be a way round it so the best advice is not to bother and only show things at a resolution where you don't mind people using it.
You can watermark images but then you're stopping the photo from being seen in it's full glory. Unless you watermark it at the very edge, but then people can grab the image and crop out the watermark.
You really can't stop people so don't try. Just accept the sharing, 'everything is free' nature of the internet. It works both ways. You get access to a lot of free stuff too so it's fair to give something back.