It is so annoying if someone copies(thefts) your blog posts,articles,images and another kind of information owned by you saying that they are the original owners of the content.
But,I think 'disabling right click' is not the right solution for that.
Most people come to your site to read information and very small percentage of people come to your site to steal your work,images,etc.So,most people feel it insulting and I think it's very unprofessional thing to do
If you want to protect your images,my suggestion is to add a Watermark(logo) of your sitename,or your name on the images,pictures,etc.
That's all my personal opinion,However if you despirately want to add this feauture,You can get this code here.
Where to paste it in blogger ?