+1  A: 

In my opinion, Jurgen Appelo's site is awesome.

http://www.noop.nl/

http://feeds.feedburner.com/noop

Ryan Lanciaux
+1  A: 

I love Johanna Rothman's blog Managing Product Development.

Mark Biek
+1  A: 

From a management standpoint, there are two that I love (not IT specific):

  1. Rands in Repose -- management observations
  2. Manager Tools -- a blog and a series of great podcasts on managing people
Guy Starbuck
A: 

Two that I read:

How to be a Good Product Manager
The Cranky Product Manager

DGentry