There are many websites out there with useful information about photography, and many photographers regularly posting great photos.
Here's some photography-related blogs that I read on a regular basis (via Google Reader). Hopefully you'll find some of the blogs on this list useful.

• A Little News
• Annual Report Photographer David Tejada
• Arlene Bax Blog
• Alex Wise Photography
• Chase Jarvis Blog
• chromasia.com photoblog
• Confessions of a Photographer
• David E Jackson // A Blog
• Digital Photography School
• Flash Frog
• Flash Flavor
• Jasmine Star Photography Blog
• Jessica Claire - Photographer
• Joe McNally's Blog
• Mark J Reblias Blog
• mulletgod.org - a music and photography blog
• Neil Creek - Photographer
• Nigel Honey Photos
• No Cropping Zone
• SDuffyPhotography.blog
• Spool Photography Landscape Blog
• State of the Nation
• Strobist
• Todd Norbury's Photography Blog
• Zack Arias - Atlanta based editorial music photographer

Update (Feb 2009): added a few additional links.
Update (Aug 2009): added more links.

While not specifically photography-related, I thought I'd post this information, as all webmasters and people running websites should be aware of it, as AVG LinkScanner could be causing additional bandwidth usage on your websites, and falsely inflating your website hit counts.
Also, anyone with AVG Anti-Virus Free 8.0 needs to be aware of this behaviour, that it will consume additional download quota as LinkScanner queries every result on a search engine results page, and that it is having a negative impact on websites.