1.Download NoDoFollow plugin from here
2.Install it and restart firefox
3.If you want to check a blog is do-follow or no-follow, right click on any part of your webpage
in firefox and click NoDoFollow. Do-Follow links turns BLUE and No-Follow turns RED.
NoDoFollow Add-on for Firefox 6 , firefox 7 and firefox 8
https://connectwww.com/nodofollow-add-on-for-firefox-6-firefox-7-and-firefox-8/1256/
For firefox 5
https://connectwww.com/nodofollow-add-on-for-firefox-5/1057/
For firefox 4
https://connectwww.com/nodofollow-add-on-for-firefox-4/923/