How can I setup side bar in blog ?

Hi,
I am setup blog. Please look here # https://www.webhostingpeople.net/category/blog

Now please click any post or look https://www.webhostingpeople.net/introduction-to-ssl-secure-certificate.html

I want same left Side bar in https://www.webhostingpeople.net/category/blog as you are looking in https://www.webhostingpeople.net/introduction-to-ssl-secure-certificate.html

Please guide me How can I do this ?