I follow multiple artist blogs, many of which are veterans in their respective industries. While reading alone will by no stretch make you a better artist, there are always tips that an be picked up from literally anywhere. Art is one of the few professions in which all of the information that you REALLY NEED in order to be successful can be placed out in the open without restriction.
There are far too many good articles out there to list in one place, and if I tried to link everything I came across that looked useful this blog would become very watered down with other peoples' opinions indeed. That said, I have found a few good links worth your attention. I'll try to do a few more of these whenever I collect a good batch of links.
John Schindehette - Artist as Brand, Part 1: John Schindehette works as Art Director for Wizards of the Coast, but he is a genius when it comes to the business of art. Highly recommend browsing his entire blog archive, not just this entry.
James Gurney - Line Direction: Short, direct, but highly informational.
Mark Kenndy - The Environment Should Also be a Character: More validation for why one needs to know about drawing EVERYTHING, not just cute characters.