A list of the sites I found on March that I enjoyed the most and visited often:
Smashing Magazine delivers useful and innovative information for web-designers and web-developers. It was founded in August 2006 by Sven Lennartz and Vitaly Friedman, and it is a huge success already. The secret to its incredibly fast growing popularity is very simple: absolutely GREAT articles.
Threadwatch.org is a community website focused on Internet marketing and related technologies. It is an excellent reference for SEO.
Digg is almost synonym to Social Media (SM). There are now tons of similar sites, and some that I would probably enjoy more, since Digg has become very crowded, and has many topics I do not “digg”. Anyway, Digg is probably the best place to get started with SM.