Here's a list of some of my preferred blogs on this music we commonly refer to as "jazz," in no particular:
Darcy James Argue's Secret Society - Argue is a McGill alum, and a fantastic composer and big band leader now residing in NYC.
Greenleaf Music - Dave Douglas' new record label, with essays and posts by Dave, Mike Friedman, Adam Benjamin (keyboardist of Kneebody) and others. I'm personally partial to this essay by Dave on the validity of improvisation
Do the Math - a blog belonging to the Bad Plus.
Jessica Williams - the pianist's personal blog.
be.jazz - reviews and links from a Belgian jazz aficionado, Mwanji Ezana. Contains many more links on the sidebar.
And if that's not enough linkage for you, All About Jazz has their own list of blogs.