Check out this website: http://www.musicthinktank.com/ - I subscribed to their daily email updates and I gotta say, they are jam packed with useful tips for the working musician. I highly recommend it - I love the daily email. Check it out!
And if you want to linger on the site you can find literally hundreds of things to read and learn. Tips on everything from using social media to recording tips to legal issues. Enjoy!