I always enjoy reading the Pragpub e-magazine (I download the .mobi edition for my kindle). And this month has some great articles about the Arduino in it. Well worth a peek.
If you haven't looked at this magazine series before it's probably time to look now.
If you haven't heard of the Pragmatic Coder (and now the whole bookself website) It's definitely time to have a peek. I have quite a few books from this site waiting to be read at the moment.