Brent Ozar is king. http://brentozar.com — The best resource for FREE SQL training. Brent’s team hosts a weekly webcast on Tuesdays. There is also an abundance of videos and HOWTO articles posted on the blog page.
Microsoft / Tech
Scott Hanselman is an excellent speaker. His technical content is geared towards C# / ASP.Net developers, but I routinely read his blog because he frequently posts on “general tech” / “general Microsoft” items.