Exactly, this is the easiest way. I use LinkParser (available for Chrome and Firefox) - when you turn it on it highlights dofollow links in green and nofollow in red. Alternatively, you could look at the source code. Either right-click and select "show source code" or install another add-on/extension called Firebug (or a similar).
I use NoDoFollow addon in my Firefox. Not all backlinks are created equal, most of the high DA sites allows us to add do-follow links. Most of the social bookmarking sites are no-follow. No follow backlinks from SB sites gives more traffic.
Simply, right click on the link and choose inspect. If you see no-follow in the code then it is a no-follow link otherwise its a do-follow.