I recently heard about the Problogger site dedicated to those who want to become bloggers on a professional level (i.e., full-time job earning money). As part of their current 31 days project they have a great collection of hints and tips on all facets of blogging including writing entries, building a blog brand name, marketing your blog, indexing in search engines, responding to commentors, interface design, traffic behavior, etc.
I find that we ourselves learned some of these best practices on blogging (by trial & error), and there are still many other things to learn from. We are sharing these practices with our different teams in applications development, design, marketing, and community relations.
If you are a blogger--even if you're not in it for the money--read this site.
Lots to learn from Problogger's 31 days to building a better blog