All these directories will help your SEO and Page Rank.
Yelp – they have a very strong presence in San Francisco.
Google local
Yahoo local
CitySearch which recently bought InsiderPages
JudysBook
SFstation Business Directory
If you have a specific product that can be promoted try to submit to Daily Candy
Make a free craigslist ad for “skilled trade services”. It will appear in this section:
http://sfbay.craigslist.org/sfc/sks
Mine is super simple:
USE MY IMAGINATION.
HelloARI is a full service boutique studio offering turnkey solutions for small businesses with a strong focus on web design: art direction, html and css production and content management systems (WordPress and Drupal). Non-profits welcome.
Learn more on my website: http://www.helloari.com/portfolio
and read my testimonials on Yelp: http://www.yelp.com/biz/helloari-design-san-francisco
Email or call 415.621.4268 for more information.