How does yahoo answers work..after you submit an answer can you put a link back to your site, is that really allowed or even a signature.
Blog commenting was always a good method for me. I'd save a selection of blogs in my RSS feed client and visit them every couple of days and comment on posts that interested me. You can find blogs by typing "Powered by wordpress" and then your niche into Google. Guest posting is something I'm starting to get into and I started by finally approaching the owners of the blogs I had been commenting on for a while.
Posting on forums that allow DoFollow links in signatures and also have a high PR is a good way to create backlinks.
directory/article submission blog commenting you post good quality and unique content to your blog Although, i heard from some people saying that submission is no longer effective as google didn't pay attention to it anymore, but I would like to say that it is worth trying it. As you will get BL once accepted. Goodluck