1) Brass Goggles. http://brassgoggles.co.uk/brassgoggles/
The best steampunk blog, and a great community forum, too. You really need to check it out.
2) The Steampunk Home http://thesteampunkhome.blogspot.com/
Described thusly "Join me as I search for items for my house that combine the scientific romanticism of the Victorians with our real present and imagined future."
If you're looking to steampunk your home, this is the site you need.
3) The Traveler's Steampunk http://steampunk-blog.dailysteampunk.com/
That's their mis-spelling of traveller, not mine. Good site, though, if you want to learn more about the steampunk lifestyle.
4) The Steampunk Librarian http://steampunklib.vox.com/
An informative site, which seems to have a lot of interesting links in each post.
5) Adventures in Steampunk http://steampunkadventures.blogspot.com/
Bringing to you inventions and interesting news of the steampunk variation.
Not Wanting to blow my own trumpet, but as an added extra...
Steampunk World - I won't include a link as you are here
Writing Advice with a steamy twist
News of the steampunk kind