I'm sure most of you read these sites anyway, but just in case...
I thought Nettuts ran a pretty sweet article about jQuery and it's hidden features by James Padolsey. For example, I always forget how awesomely easy it is to serialize from inputs (like for AJAX submission). Serialize = find all the inputs in the form and build a query string with the name/value pairs, instead of doing all that yourself/hard coding it.
Then Smashing Magazine ran a great one by Andy Rutledge answering common questions about design professionalism. Andy is an opinionated dude and I love how he dished out some hard facts here. For example, if you are asking questions like "I'm just staring freelancing and I'm wondering how I can get more clients..." then you probably shouldn't be freelancing. Plus, a heaping helping of personal responsibility.
Jeff Starr over on Digging Into WordPress wrote up a nice guide on getting a plugin into the official plugin repository. I'm a little disappointed in myself I've never done this before. I'm not much of a deep backend dude, but still, I have a few ideas that I think would make cool plugins.
I'm gonna close comments here just because anything that needs to be said about any of these things is probably best said at that article.