ChessTeacherLessons is also an interesting site to learn and improve your chess. At the moment there are more than 100 chess lessons on almost all the stages of the game and for all levels of play on this site. I advice to start at the chess lessons index page, but you can also navigate through the site by using the tags or categories.
The site doesn’t contain chess news and isn’t very frequently updated, but I like the chess lessons.
Update february 2015
ChessTeacherlessons has been discontinued, but the chess lessons are currently being moved to freechesslessons.blogspot.com
I have updated the link above.