use one of the free blog sites to create a user friendly blog on your topic. Then link to your site from the blog and also try to promote the blog as well, which will in turn promote your website.....
I too like signature backlinks since you can do 3-4+ links in a fraction of the time of submitting to a directory, writing and submitting an article, commenting on a blog when most are PR0 anyways.
I also submit my higher trafficked articles and content to qassia. They have an awesome system for building out your link footprint.
comment on dofollow blogs and in combination, and also if you are using a blog add a "comment luv" plugin on wordpress.
I think the most common methods will be commenting on do-follow blogs, etc. However, you can also have some contest, I am sure that people will link up your site to introduce more people into the contest or something.
Nice insight to importance of backlinks. Do search engines frown upon getting mass amounts of links in small periods? If so does anybody know any rough guidelines on the limits which the search engines start to penalise?
I prefer Social bookmarking sites.. However,I don't know which social bookmarking and networking sites are dofollow and which is not dofollow.. How can I learn dofollow social bookmarking sites.
You miss something, the more links you have from a domain, the less important those links become. So you better have one-two good links from a domain than 100, really.