General sites that aggregate content worth reading from around the web:
Economics blogs (alphabetical order by title):
The Conscience of a Liberal (Paul Krugman)
Grasping Reality with Both Invisible Hands (Brad DeLong)
Library of Economics and Liberty (Bryan Caplan, Arnold Kling, David Henderson)
Marginal Revolution (Tyler Cowen and Alex Tabarrok)
Overcoming Bias (Robin Hanson)
Vox (Richard Baldwin/CEPR)