How To Use Blog Commenting to Create Free Leads and Drive Traffic.
If you want to get lot of info about seo and about this question then check this:

http://seofreetricksnet.blogspot.com/2012/02/how-to-use-blog-commenting-to-create.html

Very useful info is there,
Thank you a lot for this sharing.

You should do blog commenting on niches blog which will give you a good quality of backlink. It also increase the website visitor. I mostly prefer to do these blog comment to increase the page rank of the website.

I have observed two plug-in keywordLuv and CommentLuv are being used widely among wordpress blogs and due to those comment, you can use your targeted keywords as your name which can improve to get ranking in SERP and due to second, your recent post from blog would get displayed along with your comment. So try to get list of blogs with these two plug-in.