megcabot -- Meg Cabot's syndicated blog, is on my friends list of all teen writers (and the people who love them).
Also Alex Flinn, author of Breathing Underwater, Nothing to Lose, and the forthcoming Diva: alixwrites
Laura Ruby, author of the forthcoming Good Girls: lauraruby
Maryrose Wood, who doesn't seem to post much but that doesn't stop her from being the author of Sex Kittens and Horn Dawgs Fall in Love: maryrose_wood
As always, my real blog is NOT THIS THING YOU'RE READING
The real one is syndicated thru LJ at elockhar