Adventure Cycling Blog is the go to place for bicycle tourists planning trips across the US. From maps and gear to advice and reviews this blog is the leader of the Cyclo touring pack.
Bike Radar is a very good all around blog covering racing, commuting and recreational cycling. They have a very extensive and in depth review section for bikes, parts, clothing apps and more. I think their lean is more toward the racing side but you should be able to get plenty of information on just about every aspect of biking.
This is an effort to create a master list of Global bike blogs. I will be posting links to existing blogs I am aware of and hope readers will send me their favorites.
Bike Snob NYC is perhaps a little snarky but the name imply s that. This guy actually rides and has an opinion on everything cycling. This is a good blog to frequent if you want to do a little thinking beyond basic observation of the cycling culture.