If you are using Firefox you can install SearchStatus add-on to check google pagerank and alexa pagerank for the website that you are visit.
This tools is very simple in viewer, you can decide to see where the rank will be shown on your firefox. When you open website you will get information about page rank and alexa rank of the site. You can also highlight link with nofollow attribute.
If you want create backlink so this tool will help you to see what is website rank and if the website have nofollow attribute for another url or not.
You can install SearchStatus from here