How to add right sidebar to a single post page?

Hello!

I’m building a website based on two themes: Appliance for blog main page and Tempera for every else page (front page, all subpages and single blog posts).

Would like to add the right sidebar to single post page (I’m gonna place some there widgets – the archive, last comments and so on).

Could you please give ma a clue how to do it? I suppose it’s an easy move, but I cant deal with it after all.

Greetings and thank you for such a functional, responsive theme!