The plugin is very straight forward. By default, all Blogroll links in WordPress have a nofollow tag attached to them so that Google Page Rank juice is not passed to them. This plugin allows you to remove the nofollow tag for all links or all links excluding the home page.
Best Blogroll is a good plugin though I would only recommend it to those who have a large Blogroll and a requirement that each link passes PR juice to their link partners. For everyone else, I would keep the nofollow tag in their Blogroll links so that your outgoing PR juice is not greatly reduced.
More information about the plugin can be found at the link below.
Link: Best Blogroll