To add disclaimer in a blog

Currently i am working on a few blogs, and I would like to display a few messages on all pages of my pages, easily visible to users.

What's the html coding to do it?

I would like to provide the message on the right-hand side of my blogs above/below Blog archive.

N.B: Please provide me only useful replies or links, and avoid useless posts like "search google", or full tutorial links etc :)