How to change sidebar font

To change sidebar font in the DW Minion theme, please follow the jetpack’s guideline in the Blog article on how to use Edit CSS here. http://designwall.com/blog/using-jetpack-custom-css-for-your-wordpress-site/
After that, just add the following code to the Edit Css.

.site-nav {
    font-family: 'Roboto',"Helvetica Neue",Helvetica,Arial,sans-serif;
}

#secondary {
font-family: ‘Roboto’,”Helvetica Neue”,Helvetica,Arial,sans-serif;
}

Notice: You can find the font here: http://www.google.com/fonts/#   Hope this helps !