Planet Erlang by Process-one is a blog that aggregates articles from other Erlang information sources. You can register and submit links to articles into a candidate pool. Once enough other members voted for such a candidate it gets published to the front page / main feed.
The site also features many RSS feeds for various topics.
Yariv's Blog by Yariv Sadan seems to be the first Erlang blog around and has gained a high visibility. He writes about his strange adventures in Erlang and is quite funny sometimes.
Today Your Bear tought it might be a good idea to ask the #erlang crowd on irc.freenode.net about Erlang blogs. It was responded by the enthusiasm which is so typical for #erlang.
Torbjörn Törnkvist's "The Red Hot Erlang Blog" is already interesting because the blog is implemented in Erlang. Topics vary from Erlang insights to web development.
James Hague's "Programming in the 21st Century" is one of the most interesting Erlang blogs around. James combines experiences from 80ies games programming in assembler with insights into Erlang. He shows us how low level still matters in the world of the high level.
This blog by Roberto Saccon seems to care mostly about creating web applications, with Erlang on the server side, JavaScript in various prominent support roles and some other web culprits.