KindleBoards.com - Another very active Kindle board.
Reversing Everything - MobileRead member igorsk dissects the software and hardware of Kindle 1 and Kindle 2.
Massively Parallel Procrastination - Jesse Vincent's blog on the creation of Savory for Kindle 2 and various other projects
iReaderReview - switch11's very prolific blog (a personal favorite).
Kindle Forum, Kindle Social Network - a Kindle Social Networking site.
Kindle Formatting - Joshua Tallent's site on how to best format your ebook for the Kindle. He also offers formatting services.
The Kindle Chronicles - Len Edgerly's weekly podcast. Interviews, tips and tricks. Can be subscribed to via iTunes or downloaded directly from the website (and you can listen to it on your Kindle!)
The three blogs that I check daily are:
Amazon's Kindle Blog -- this is the same as the "Kindle Daily Post" item in the Kindle Storefront page in the Kindle itself. Using my browser means I don't have to turn on the Kindle's antenna just to see what Amazon might be promoting.
The Kindle Reader -- an almost daily posting with links to books for the Kindle. Most links are to Amazon, but sometimes to MobileRead or other sources for books.
Books on the Knob -- the site says "Bargain reads, book reviews, the Amazon Kindle and some games, technology and computers tossed in now and then."