Yes I agree with you social networking sites is extremely effective tool for promote a blog but its better to use high PR and dofollow sources for promotion.
when you are into blogging, you should to all steps carefully not like you are in rush. first thing is to make network with other bloggers, this will help you a lot.
You can summit your blog to directories or just go on forum and put it in your signature. You can also comment on other blog related to your topic. Good luck. It it a lot to work
You can comment on other blogs, stay active in niche forums, write articles and submit them to article directories.
make article postings and keep there your link, make blog postings and forum posting with link, make regular tweets on your blog postings.
The best way is to guest blogging in related niche blogs. Try to persuade the other bloggers to guest blogging.
Even i know so many ideas about promotion but any ideas how to start blogging i mean on which topic should i start
Blog comments are a very effective way to get natural inbound links. But it’s better to comments only on high PR and dofollow sites.Always use original content because duplicate content generally occupy low ranking as comparison to original content.
Do link exchange with your niche related website/blog. This thing will worth your time when you see good result in search engine ranking.
Make one post daily. Content of blog is really informative quality unique content. Do blog commenting & forum posting
I think you should first build your site content. Then make friend with other, especially in social networks. Others: - Comment on other blog - Guest post - Submit to Directory. - Buy text link/ad on high profile sites. I think guest post is one of the best method so far though it is not easy.
buy backlink is the easy way to get backlink, but it take cost, but if you have much money, i think it's no problem to paid a link service.