Dofollow forum are the best way to increase back link of your blog and traffic too.If your blog is newly launched and you wish to drive more traffic to your website you need to increase dofollow backlinks of your website.Because Dofollow backlink are identified as quality backlink by Search Engine,so as your blog has more do follow backlink more the credit your website have in search engine’s mind.(Although Search Engine has not mind but algorithm has set in such way).
You can use signature as backlink to your website in forum here are some of the forum website which provides user to add signature link.
Webmaster/SEO & Internet Marketing
International Webmaster forum
16.Australia – http://www.australianwebmaster.com
17.Phillipines – http://forums.seo.ph
18.IRISH – http://www.irishwebmasterforum.com
19.UK – http://www.davidcastle.org/BB
I will not advice you to be active in all of this forum but you can choose any 2 or 3 forum whichever you like and start posting there to add some credits in your readers mind about your blog by adding signature link at the bottom.Please do share the forum if anything I have missed and you are contributing a lot because it is not possible to add all the do follow forum link here because there are so many forum in the www so I included the best of them here.