Well, for promotion of my new site, I am thinking to submit article to free article directories list. I have one article now. Can I submit the same article to all article directories present in the list or do I need to write many unique articles and submit to different article directories? Which one will carry more link value and SEO friendly? Thanks in advance.
Regarding to article directories: A link is only worthy from trusted sites as ezinearticles, buzzle.com and other 20 article directories. If you want to have the best value you should post unique articles to each directory. However, in these days, links from article directories does not carry much weight. They only carry weight when a webmaster republish your article in their websites. If that is the case, you should contact the webmaster offering a unique article in exchange of keeping your links in the article. That is the best value of article directories.
You're better off with multiple articles spread across many sites. Ezinearticles is pretty good. I'd start there.