Dofollow links have more power for increase your blog/web site search engine visibility. Because of Google follow dofollow links. So its better if you can create more dofollow backlinks to your site. However most of the people don't know how to find dofollow links in any web site.

Hubpages allows dofollow backlinks only if your content meets these criteria. Know the rules, avoid getting BANNED from Hubpages for violating their terms of service...the Hubpages backlinking policy is one of the most complicated and intelegent one on the internet today, and not all links you place on your Hubs are dofollow (that is has SEO weightage). So here is a look at exactly which (or rather when) Hubpages links become dofollow from nofollow (or vice versa).

Step-by-step tutorial on how to make thousands of backlinks fast

"First things first, I have to clarify here that when I say forum backlinks, I am talking about the backlinks you get from forum profile pages and not the backlinks you get from signatures when posting on forums. Although, some of the tips here will be about signature backlinks too, so pay attention"